JP2000069275A - Image processing apparatus and image processing method - Google Patents

Abstract

(57) [Problem] To perform a boundary process such as an edge emphasis process on halftone data determined to be a boundary line so as to bring the halftone data closer to the value of the boundary line, thereby forming a boundary at the halftone data portion. A thinner line is suppressed to provide a higher quality image. SOLUTION: An editing area is designated by marker processing or the like,
When performing the process of filling the area surrounded by the boundary line, edge enhancement is performed on the black line image that determines the boundary in advance, and the black image density near the boundary is increased, so that the black line image and the filled image at the boundary portion are Is narrowed, making it difficult to see white spots near the boundary line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and an image processing method for processing an input image.

[0002]

2. Description of the Related Art Conventionally, an image processing apparatus having an image editing function, such as a digital color copying machine, has an area memory as a memory for area editing, and an area signal developed in the area memory in advance is used as an image when generating an image. Processing of synchronously outputting and switching each function using the output signal has been widely used. As a means for specifying an area, there are a method of directly specifying an area with a pen or a marker using a pen input with a digitizer, a color marker, or the like, and a method of specifying a closed loop area surrounded by an image of a document.

[0003] The information of the editing area designation by the marker is C
It is read as an electric signal by an image reading device such as a CD, and is written in a memory after performing a process such as A / D conversion together with image information of the document.

On the other hand, an editing area is designated by a pointing device by reading image information of a document into a memory by an image reading device and then writing data to a memory address corresponding to a predetermined position on the document by a CPU or the like. The area designation information is stored in the memory. After that, an editing area is set by performing an operation in the memory using an area generating IC or the like, and editing processing is performed on the area specified as the editing area.

FIGS. 16 to 19 show an editing area in which an editing area is specified by a digitizer or a marker.
This shows a state in which predetermined editing is performed, and the print result is shown on the left side of the document and on the tip side (right side) of the arrow.

FIG. 16 shows an example of a print result when an edit area is indicated by indicating one point using a marker. The inside of the area surrounded by a black line including a portion designated by the marker is shown. Is the editing area.

In this case, the editing area indicated by one point by the marker is temporarily stored in the memory, and is generated by an area generating circuit (for example, an area generating I / O constituted by a one-chip IC or the like).
C. The editing area is set by extending the editing area to the inside of the figure shown in black using). Then, the editing process is performed on the editing area (see FIG. 1).
6, a process of printing oblique lines is performed.)

FIG. 17 shows an example in which an editing area is designated by a closed curve using a marker. In this case, the editing area is an inner area surrounded by a closed curve drawn by a marker, and a process of printing oblique lines inside the closed curve is performed (the closed curve specified by the marker is not printed).

The example of FIG. 18 is an example of one-point instruction by a digitizer, and the print result is the same as that of FIG. When the editing area is specified by the digitizer, unlike the marker, the information for specifying the editing area cannot be obtained from the image reading device.
The editing area is specified by writing data for specifying the editing area at a predetermined position later.

FIG. 19 is a diagram showing a 2 set by the digitizer.
It is an example of specifying a rectangular area having a point as a diagonal.

As described above, when the editing process shown in FIGS. 16 to 19 is performed, before the printing operation is performed, the editing region specified by the marker and the digitizer is edited by using the region expanding circuit. Extension work needed to be done.

More specifically, in FIGS. 16 and 18, it is necessary to perform a process of extending the editing area on the original specified by a point by a marker or a digitizer to the entire area inside a closed curve indicated by black as a boundary. is there. In FIGS. 17 and 19, it is necessary to designate a closed curve indicated by a marker and the inside of a rectangle having two points specified by a digitizer as diagonals as an editing area.

Therefore, when designating an editing area as shown in FIGS. 16 to 19, an image is read by an image reading device and stored in a memory in order to set the editing area (hereinafter, an original reading operation for this purpose). Is referred to as “prescan”), and the above-described editing area expansion work is performed on the data in the memory using an area expansion circuit (area expansion IC).

When the expansion of the editing area is completed, the original is read again from the image reading apparatus for printing (hereinafter, the original reading operation for this is referred to as "main scan").
The data of the editing area is output from the memory in synchronization with the read image data, and the editing process is performed on a portion corresponding to the editing area on the image data according to the editing area data.

In the above conventional example, when an area signal is generated in an area memory, usually, a read image is binarized and the result is used as an area signal.

[0016]

However, if the area signal obtained in this way is subjected to an editing process by an area designating method, for example, in which the inside of a closed loop of a boundary line is painted, a printed image is obtained. On the upper side, halftone data determined to be a boundary line during binarization remains between the region where the editing process has been performed and the boundary line, so that the boundary line becomes thin in this portion.

[0017]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems.
By performing boundary processing such as edge enhancement processing on the halftone data determined to be a boundary line by value conversion processing or the like, the halftone data is brought closer to the boundary line value, so that the boundary line is thinned in the halftone data portion. An object of the present invention is to provide a higher-quality image while suppressing the occurrence of the image. As one means for achieving the object, for example, the following configuration is provided.

That is, an area designating means for designating a region of the processed image, an edge enhancing means for performing edge enhancement processing on a boundary of the area designated by the area designating means, and a boundary of an area edge enhanced by the edge enhancing means. And image processing means for performing predetermined image processing on the processed image within the image processing apparatus, thereby reducing a change in image quality near the boundary.

[0019] For example, the image processing means is characterized in that the area specified by the area specifying means is filled with a predetermined color or image.

For example, there is provided an instruction means for instructing image processing, wherein the image processing means performs image processing only when image processing is instructed by the instruction means.

Further, for example, the area designating means sets an area surrounded by a boundary line of a predetermined color as a specified area, and the edge enhancing means increases the image density of the predetermined color near the boundary line to increase the image density at the boundary. It is characterized in that a gap between an image and an image processed by the image processing means is narrowed, and a change in image quality near a boundary line is reduced.

Further, for example, the edge enhancing means is a process for expanding a boundary image inward and expanding the boundary image in an inward direction.

A first extracting means for extracting data for designating an image area from the input image data; a second extracting means for extracting data serving as a boundary of the image area from the input image data; An emphasis means for emphasizing the edge of the data with respect to the color data corresponding to the color of the boundary line extracted by the second extraction means, and a data designating the image area extracted by the first extraction means are compressed. First compression means for generating first compressed data, first storage means for storing the first compressed data, and second compression data by compressing data output from the emphasis means. Second compression means for generating, second storage means for storing the second compressed data, data stored in the first storage means, and data stored in the second storage means To calculate Calculation means, third storage means for storing a calculation result by the calculation means, and compressed data stored in the first storage means with reference to data stored in the third storage means. Data decompression means for decompressing, a processing area determination means for determining a processing area from data decompressed by the data decompression means, and a predetermined image according to a processing signal output from the processing area determination means for input image data. Image processing means for performing processing.

For example, there is provided an instruction means for instructing image processing, and the image processing means performs image processing only when the image processing is instructed by the instruction means.

Further, first extracting means for extracting data for designating an image editing area from the input image data, and second extracting means for extracting data serving as a boundary of the image editing area from the input image data. A density level converting unit for replacing the data density of the color data corresponding to the color of the boundary line extracted by the second extracting unit with a higher level; and an image editing area extracted by the first extracting unit. First compression means for compressing data to be generated to generate first compressed data, first storage means for storing the first compressed data, and compression of data output from the density level conversion means. A second compression unit for generating second compressed data by the first storage unit, a second storage unit for storing the second compressed data, and a second storage unit for storing the data stored in the first storage unit. hand Calculating means for performing an operation using data stored in the memory, third storing means for storing a result of the calculation by the calculating means, and the third means referring to the data stored in the third storing means. Data decompression means for decompressing compressed data stored in the first storage means;
Area determination means for determining an image processing area based on the data expanded by the data expansion means, and image processing means for performing image processing on the input image data in accordance with a processing signal output from the area determination means And characterized in that:

Furthermore, first extracting means for extracting data for designating an image editing area from the input image data, and second extracting means for extracting data serving as a boundary of the image editing area from the input image data. Means, and first compression means for compressing data designating the image editing area extracted by the first extraction means to generate first compressed data;
A first storage unit that stores the first compressed data, a second compression unit that compresses data extracted by the second extraction unit to generate second compressed data, A second storage unit for storing data, a calculation unit for performing a calculation using the data stored in the first storage unit and the data stored in the second storage unit, and a calculation result by the calculation unit; A third storage unit, a data expansion unit for expanding data with reference to data stored in the third storage unit, and a processing area determined based on the data expanded by the data expansion unit. Area determining means for outputting a processing signal; and a stretching area for generating an area signal for expanding data from the processing area determined by the area determining means with respect to the boundary line data extracted by the second extracting means. A generation unit, by the region signal stretching produced by the stretching region generating means,
Stretching means for stretching data on the boundary data extracted by the second extracting means, and image processing means for performing image processing on the input image data in accordance with a processing signal output from a region determining means. It is characterized by having.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, a digital color copying machine will be described as an example of an image processing apparatus.

[First Embodiment] An embodiment of the present invention according to the present invention will be described in detail below. FIG. 1 is a schematic sectional view of a color image forming apparatus according to an embodiment of the present invention. In the embodiment shown in FIG. 1, a digital color image reader unit is provided at the upper part, and a digital color image printer unit is provided at the lower part.

In the first embodiment described below, in order to suppress the gap between the black line image and the filled image, which occurs when the inside of the closed loop of the black line image is filled with marker processing or the like, the vicinity of the boundary is previously determined. Increase the density of the black line image.

In the reader section, the original 30 is placed on an original platen glass 31, and a known original scanning unit including an exposure lamp 32 is driven by an optical reading drive motor 35 to a predetermined fixed magnification determined according to a preset copy magnification. Exposure scanning is performed at a speed.

The reflected light image from the original 30 is condensed on a full color sensor (CCD) 34 by a lens 33,
A color separation image signal is obtained. As this full-color sensor, R (red), G
A three-line CCD provided with (green) and B (blue) filters is used. The color-separated image signal is subjected to image processing by an image processing unit 36 and a controller unit 37, and is sent to a printer unit.

An operation section is provided around the platen glass 31, and switches for setting various modes relating to a copy sequence, a display for display, and a display are arranged.

In the printer section, a photosensitive drum 1, which is an image carrier, is rotatably supported in the direction of an arrow. Around the photosensitive drum 1, a pre-exposure lamp 11, a corona charger 2, a laser exposure optical system 3, a potential sensor 12, four developing units 4y, 4c, 4m, and 4Bk of different colors, an on-drum light amount detecting unit 13, a transfer device 5, and a cleaning unit 6 are arranged.

In the laser exposure optical system 3, an image signal from a reader unit is converted into an optical signal by a laser output unit (not shown), and the converted laser light is reflected by a polygon mirror 3a, and is converted into a lens 3b and a mirror. 3c, and is projected on the surface of the photosensitive drum 1.

At the time of image formation in the printer section, the photosensitive drum 1 is rotated in the direction of the arrow, and the photosensitive drum 1 after having been neutralized by the pre-exposure lamp 11 is uniformly charged by the charger 2 so as to emit light for each separated color. The image E is irradiated to form a latent image.

Next, by operating a predetermined developing device, the latent image on the photosensitive drum 1 is developed, and a toner image is formed on the photosensitive drum 1 using a resin as a base. The developing device has an eccentric cam 24.
By the operations of y, 24m, 24c, and 24Bk, the photosensitive drum 1 is selectively approached in accordance with each of the separated colors.

Further, the toner image on the photosensitive drum 1 is
The image is transferred from one of the preselected recording material cassettes 7a, b, and c to the recording material supplied to a position facing the photosensitive drum 1 via the conveyance system and the transfer device 5. The selection of the recording material cassette is performed by driving any one of the pickup rollers 27a, 27b, and 27c according to a control signal from the controller unit 37 in advance according to the size of the recording image.

In the present embodiment, the transfer device 5 includes a transfer drum 5a, a transfer charger 5b, an attraction roller 5g opposed to an attraction charger 5c for electrostatically attracting a recording material, an inner charger 5d, and an outer charger. A recording material carrying sheet 5f made of a dielectric is integrally stretched in a cylindrical shape in a peripheral opening area of the transfer drum 5a which is rotatably driven and has a container 5e. The recording material supporting sheet 5f uses a dielectric sheet such as a polycarbonate film.

As the drum-shaped transfer device, that is, the transfer drum 5a is rotated, the toner image on the photosensitive drum is transferred onto the recording material carried on the recording material carrying sheet 5f by the transfer charger 5b.

As described above, a desired number of color images are transferred to the recording material sucked and conveyed to the recording material carrying sheet 5f, thereby forming a full-color image.

In the case of forming a full-color image, when the transfer of the toner images of four colors is completed in this way, the recording material is separated from the transfer drum 5a by the action of the separation claw 8a, the separation push-up roller 8b and the separation charger 5h. The sheet is discharged to the tray 10 via the roller fixing device 9.

On the other hand, the post-transfer photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned by the cleaning device 6.

When forming images on both sides of a recording material,
Immediately after the fixing device 9 is ejected, the conveyance path switching guide 19 is driven, and once guided to the reversing path 21a via the conveyance vertical path 20, the rear end of the reversing roller 21b is moved forward by the reverse rotation of the reversing roller 21b. And is retracted in the direction opposite to the direction in which the sheet is fed, and stored in the intermediate tray 22. Thereafter, an image is formed on the other surface again by the above-described image forming step.

Further, in order to prevent scattering of powder on the recording material carrying sheet 5f of the transfer drum 5a, adhesion of oil on the recording material, and the like, the fur brush 14 and the recording material carrying sheet 5f pass through the brush. 14, a backup brush 15, an oil removing roller 16, and a recording material carrying sheet 5.
Cleaning is performed by the action of the backup brush 17 facing the roller 16 via f. Such cleaning is performed before or after image formation, and when a jam (paper jam) occurs.
It is performed as needed when it occurs.

Further, in the present embodiment, the eccentric cam 25 is operated at a desired timing, and the transfer drum 5f is operated.
By operating the cam follower 5i integrated with the photosensitive drum 1, the gap between the recording material carrying sheet 5a and the photosensitive drum 1 can be arbitrarily set. For example, during standby or when the power is off, the interval between the transfer drum and the photosensitive drum is increased.

FIG. 2 is a diagram showing the internal configuration of the image processing unit according to this embodiment. 2, reference numeral 201 denotes a shading correction circuit; 202, an input masking circuit;
Denotes an RG editing circuit, 204 denotes a color space compression circuit, and 205 denotes a light amount-density conversion (hereinafter, referred to as “LOG conversion”) table.

206 is an output masking circuit, 207 is C
An MYK editing circuit 208 is a density correction table. 2
Reference numeral 09 denotes a scaling circuit, 210 denotes a spatial filter circuit, 211 denotes a black character processing circuit, and 212 denotes an area generation circuit.

The image read by the CCD 105 and converted into digital image signals R, G, and B by the amplifying device 106 is input to the lamp light source 10 by the shading correction circuit 201.
The inclination of the light distribution and the variation of the sensor are corrected. After that, the input masking circuit 202 converts the signal into three signals representing the standard color space, and inputs the converted signal to the RGB editing circuit 203.

Then, color conversion is performed by the RGB editing circuit 203,
Partial editing processing such as image synthesis with an external device and generation of a character processing signal is performed. Next, the color space compression circuit 204 compresses the color space so that the color of the document does not collapse and falls within the color reproduction range of the printer unit.

Further, in the LOG conversion table 205, the image signals RGB represented by the light amounts are converted into density signals C (cyan), M (magenta),
The signal is converted into a three-color signal of Y (yellow). The output masking circuit 206 at the next stage outputs a signal of one color for forming an image among CMYBk converted in accordance with the spectral characteristics of the toner in a frame-sequential manner. Paint with CMYK editing circuit 207,
After adding a function such as coloring, an image signal that has passed through the density correction circuit 208, the scaling circuit 209, and the spatial filter 210 is output to the laser drive circuit.

On the other hand, the black character processing circuit 211
A bold character determination unit 213 that determines the bold character degree of the image from the image signal, an edge detection unit 214 that detects an edge of the image from the RGB image signal, and a color detection unit that detects the color of the image from the RGB image signal 215, and switches the output masking 206, the coefficient of the spatial filter 210, and the number of lines for laser driving according to the determination / detection result.

The area signal generation circuit 212 generates an area signal in accordance with designation by a digitizer or a marker.

(Black Line Image Detection Processing) Next, detection of a black character / black line image in the black character processing circuit 211 of the image processing section of the present embodiment having the above-described configuration will be described.

Operation of Edge Detector 213 The edge detector 214 shown in FIG. 2 has the configuration shown in FIG. That is, a luminance calculation circuit 701 that calculates the luminance of the input color signals R, G, and B, an edge minimum direction detection circuit 702 that detects the minimum edge direction, and an edge minimum direction smoothing circuit that performs smoothing processing on the minimum edge direction. 703, an edge detection circuit 704 for detecting an edge from the data subjected to the smoothing process.

Hereinafter, a specific description will be given. The signals R, G, and B, which have been masked as described above, are output to the edge detection circuit 21.
The luminance signal Y is first calculated in the luminance calculation circuit 701 according to the following equation.

[0056]

(Equation 1)

Y = 0.25R + 0.5G + 0.25B (1) FIG. 4 shows a detailed configuration of the luminance calculation circuit 701 that calculates the luminance signal Y according to the above equation (1). The input color signals R, G, B in FIG.
After being multiplied by the respective coefficients 0.25, 0.5 and 0.25 by 802 and 803, they are added by adders 804 and 805 (1).
The luminance signal Y is calculated according to the equation.

Next, the minimum edge direction detection circuit 702 detects the minimum edge direction. FIG. 5 shows the detailed configuration and operation of the edge minimum direction detection circuit 702. FIG. 5 is a diagram for describing the detailed configuration and operation of the edge minimum direction detection circuit 702 including the edge detection filter unit according to the present embodiment.

As shown in FIG. 5, the input luminance signal Y
Are expanded by the FIFO buffers 901 and 902 to three lines delayed by one line each. Then, through the known Laplacian filters 903 to 906, a direction in which the absolute value a of the edge amount which is the output value of the filter takes the minimum value among the four directions is obtained. And the absolute value a of the edge amount
The direction in which takes the minimum value is the edge minimum direction.

Next, the minimum direction smoothing circuit 703 in FIG. 3 performs smoothing processing on the minimum direction of the edge obtained by the minimum edge detection circuit 702. By this process, only the direction with the largest edge component is stored,
Other directions can be smoothed.

That is, the halftone dot component having a large edge component in a plurality of directions has its edge component smoothed and its feature reduced. On the other hand, for a character / thin line in which an edge component exists only in one direction, the effect is obtained that the feature is preserved. By repeating this process as necessary, it is possible to separate line components and halftone components more effectively, and to detect character components existing in halftone dots, which could not be detected by the conventional edge detection method. Becomes possible.

After that, the edge detection circuit 704 removes the edge amount equal to or smaller than the absolute value a through the above-described Laplacian filter, and outputs only the edge amount equal to or larger than the absolute value a as “1” indicating the edge detection. The output signal “edge” from the edge detection circuit 704 is output to the spatial filter circuit 210 as shown in FIG. (Edge Enhancement Processing) Next, the edge enhancement processing in the present embodiment will be described.

FIG. 6 shows the spatial filter circuit 210 shown in FIG.
FIG. 3 is a diagram showing a detailed configuration of the embodiment. As shown in FIG.
Is composed of FIFO buffers 210 to 213 and a shift register group 220.

The output signal “edge” from the edge detection unit 214 is input to the spatial filter.
In the present embodiment, the filter coefficient is switched according to the content of the edge signal.

As filter coefficients, a coefficient for normal operation (a through setting when no filter is used) and a coefficient for a well-known edge emphasis filter are prepared in a bank in advance, and the edge determination signal edge is “1”. At this time, a coefficient for edge enhancement is set in the filter, and when the edge determination signal edge is "0", a coefficient during normal operation is set in the filter so that only the black line image can be edge-enhanced. Make up.

FIG. 7 shows the area signal generation circuit 212 shown in FIG.
FIG. 3 is a block diagram showing a detailed configuration of the embodiment. A marker signal, which is input data of the area signal generation circuit 212, is a signal generated inside the RGB editing circuit 203, and is a signal representing black data (K) as original image data and marker colors of R, G, and B, respectively. And 4 bits.

In FIG. 7, reference numeral 1002 denotes a thinning-out processing unit which performs thinning-out processing (data compression processing) on black data and RGB marker signals. In the thinning processing performed in the thinning processing unit 1002 according to the present embodiment, one pixel of data is thinned out and output from a 16 pixel marker signal of 4 pixels × 4 lines.

Data output from thinning-out processing section 1002 is subjected to data conversion for storage in memory 1004 by data conversion section 1003, and the converted data is stored in memory 1004.

When the data compressed for one document is stored in the memory 1004 by the prescan operation, the area expansion IC 1006 reads the data in the memory 1004 and performs processing for expanding the editing area using the boundary line data. Do.

In this embodiment, the area is extended using AGDCII, which is a drawing IC of NEC Corporation, as the area extension circuit (area extension IC) 1006. AGDCII
Has various drawing commands. Here, the area is expanded using the “paint” function.

When the area expanding operation by the area expanding circuit 1006 is completed, a main scan operation for printing is started. Then, the data conversion unit 1007 starts reading data from the memory 1004 and performs an inverse conversion process of the data conversion unit 1003.

Reference numeral 1008 denotes an interpolation processing unit,
For example, the above-described interpolation processing shown in FIG. 4 is performed on the signal indicating that the editing area is output from the editing area 04.

Reference numeral 1009 denotes an area signal control unit. When black data as a boundary line is input from the marker signal input to the area signal generation circuit 212 during the main scan, the edit signal output from the interpolation processing unit 1008 is output. Mask it.
As a result, the black portion on the document is excluded from the editing region. Therefore, of the editing region signal output from the interpolation processing unit 1008, the region other than the portion where the black data exists on the boundary is output from the region signal generation circuit. An edit area signal is output.

As described above, when the editing area is designated by the marker processing or the like and the area surrounded by the boundary line is painted, the edge enhancement is performed on the black line image which determines the boundary in advance. By increasing the density of the black image near the boundary, the gap between the black line image and the filled image at the boundary can be narrowed, and the white spot near the boundary can be made hard to see. When performing the process of filling the area surrounded by the boundary line in the present embodiment, edge enhancement is performed on the black line image that determines the boundary in advance, the black image density near the boundary is increased, and the black line at the boundary is increased. FIG. 8 shows the principle of narrowing the gap between the image and the filled image so as to make it difficult to see white spots near the boundary. FIG. 8A shows an example of a conventional image in which edge enhancement is not performed when a process of filling a region surrounded by a boundary line is performed.

The lower part (b) shows an example in which edge enhancement is performed on a black line image for which a boundary is determined in advance in the present embodiment. As shown in (b), the black line near the boundary is shown in FIG. By increasing the image density, the gap between the black line image and the solid image at the boundary can be narrowed, and the white spots near the boundary can be hardly recognized.

In this embodiment, a case has been described in which a marker is designated at one point on a document by a marker. However, in a case where designation is made by a digitizer, the area generating circuit 212 uses image data as a marker signal as a marker signal. Only certain black data (boundary line) is stored in the memory, and then the position on the document specified by the digitizer is stored in the CPU shown in FIG.
The same effect can be obtained by writing data to the corresponding position in the memory 1004 by 1005 and then performing the operation after storing the data in the memory described above.

[Second Embodiment] In the first embodiment described above, the gap between the black line image and the filled image generated when the inside of the closed loop of the black line image is filled by marker processing or the like. In the above, an example has been described in which the density of the black line image near the boundary line is increased in order to reduce the density. However, the present invention is not limited to the above example, and the edge enhancement of the black line image may be performed only when performing the marker processing. An embodiment of the second invention according to the present invention in which edge enhancement of a black line image is performed only when marker processing is performed will be described below.

In the second embodiment, the basic configuration is the same as that of the above-described first embodiment.
The description of the same configuration as that of the embodiment is omitted,
A description will be given of a portion different from the above-described first embodiment. In the second embodiment, the selection of the marker processing is selected by an operation unit (not shown).

FIG. 9 is a diagram for explaining a detailed configuration of the spatial filter 210 according to the second embodiment of the present invention. 9, the same components as those of the first embodiment shown in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 8, a selector 1301 receives an edge judgment signal e input by a select signal sel.
dge edge detection bit signal and a fixed value “0”
One of the two signals is selected, and the spatial filter 2
It is output as a coefficient switching signal fi of 10.

At this time, when the marker processing is selected by the operation unit, the select signal sel of the selector 1301 becomes “1”, the edge determination signal edge is output as it is as the coefficient switching signal “fil” of the spatial filter 210, and the spatial filter Edge emphasis processing is performed on a black line image in the same manner as in the embodiment.

On the other hand, when the marker processing is not selected in the processing section, the select signal sel of the selector 1701 becomes "0", and the fixed value "0" is used as it is in the spatial filter 2.
The spatial filter does not perform the edge enhancement processing regardless of the presence or absence of the black line image.

As described above, according to the configuration of the second embodiment, the edge enhancement of the black line image can be performed only at the time of the marker processing.

In the above-described second embodiment, an example in which the selector is used to switch the coefficients of the spatial filter has been described. However, a look-up table (hereinafter referred to as “LUT”) is also used. Needless to say, the present invention can also be realized by using a method of controlling the coefficient switching signal “fil” of the spatial filter 210 by switching the LUT bank in accordance with the select signal “sel” from the operation unit.

In the second embodiment, an example has been described in which marker processing is selected using the operation unit. However, a means other than the operation unit may be used as a marker processing selection unit.

[Third Embodiment] Next, according to a third embodiment of the present invention, the density of the black line image is replaced with a higher level, and the black line image near the boundary and the solid image are replaced. An example of correcting the gap between the two will be described. Also in the third embodiment, the basic configuration is the same as that of the above-described first embodiment. Therefore, the description of the same configuration as that of the first embodiment is omitted, and the above-described first embodiment is omitted. A description will be given of portions different from the embodiment.

FIG. 10 is a detailed block diagram of the density correction circuit 208 according to the third embodiment of the present invention. Third
In the embodiment, the density correction circuit 208
The LUT has a capacity to store density correction conversion coefficients for four colors.

An image signal input to the density correction circuit 208 in a frame-sequential manner and a toner color signal supplied as an image color identification signal sent from a synchronization signal generation circuit (not shown) serve as address information of the LUT 1401. . The image signal is the lower address and the toner signal is the upper address in LU.
It is input to T1401.

In the third embodiment, the LUT 1401
In the table, the density value slightly higher than the fruit density value in the normal operation is set in the area where the toner color is black. With such a configuration, the density of the black line image can be replaced with a slightly higher level.

If a configuration is used in which a plurality of LUTs for black density are provided, and a table having different densities is set in advance in each LUT and variably adjusted by the operation unit, an effect on the image can be obtained. You can also adjust while checking.

As described above, according to the third embodiment, the density of the black line image can be replaced with a slightly higher level, and the gap between the black line image near the boundary and the solid image can be corrected. it can.

[Fourth Embodiment] Next, a fourth embodiment according to the present invention, in which the black line image of the boundary line is expanded inward and the black line image is painted and stretched in the image direction, thereby suppressing white spots in the gaps. An embodiment of the present invention will be described. In the third embodiment, the basic configuration is the same as that of the above-described first embodiment. Therefore, the description of the same configuration as that of the first embodiment is omitted, and the above-described first embodiment is omitted. A description will be given of portions different from the embodiment.

FIG. 11 is a diagram showing the internal configuration of the image processing block 107 according to the fourth embodiment of the present invention. 11, the same reference numerals are given to the same components as those in FIG. 2 in the above-described embodiment, and the detailed description will be omitted.

In the fourth embodiment shown in FIG. 11, the area signal generation circuit 1212 and the spatial filter circuit 1212
10, the edge determination signal edge from the edge detection unit 214 is not input to the spatial filter 1210. Instead, the expanded area signal generated by the area signal generation circuit 1212, which will be described in detail later, is a spatial signal. It is input to the filter 1210.

FIG. 12 shows a detailed configuration of the area signal generation circuit 1212 according to the fourth embodiment of the present invention.
FIG. 12 is a block diagram showing a detailed configuration of the area signal generation circuit 212 according to the fourth embodiment of the present invention shown in FIG. 12, the same components as those in the first embodiment shown in FIG. 7 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

A marker signal, which is input data of the area signal generation circuit 212, is a signal generated inside the RGB editing circuit 203, and includes black data (K) as original image data and marker colors of R, G, and B, respectively. Is composed of four bits.

In FIG. 12, the operation from the thinning processing unit 1002 to the area signal control 1009 is the same as that of the area signal generation circuit 212 shown in FIG. 7 in the first embodiment.

Reference numeral 1501 denotes a stretching area generation unit unique to the fourth embodiment, which performs an operation of stretching the area of black data as a boundary line from the input editing region signal inward of the boundary line. .

FIG. 13 shows a detailed configuration of the stretched area generation unit 1501. FIG. 13 is a diagram illustrating a detailed configuration of the stretched area generation unit 1501 illustrated in FIG. 6 according to the fourth embodiment.

In the fourth embodiment, the edit area signal input to the enlargement processing unit 1501
The nine buffers are extended to three lines delayed by one line by the O-buffer 1601 (hereinafter referred to as “F”).
F ”) 1602).

The output signals of the nine FFs 1602 are input to the OR gate 1603 and the NAND gate 1604, and WIND which is the output of the FF corresponding to the target pixel of the filter
The fourth bit signal of OW is input to NOT gate 1605. OR gate 1603, NAND gate 160
4 and the output of the NOT gate 1605 are input to the AND gate 1606, and the AND gate 1606 outputs a stretched area signal.

The stretched area signal is supplied to the OR gate 160
3 is “1” (when one or more edit area signals exist in the filter area of the 3 × 3 filter), and the output of the NAND gate 1604 is “1” (in the filter area of the 3 × 3 filter). When there is one or more edit area signals), and the output of NOT gate 1605 is "1"
At the time of (when there is no edit area signal in the target pixel area of the 3 × 3 filter), it becomes “1”, otherwise it becomes “0”.

That is, when the target pixel of the filter refers to the end of the edit area (the first pixel outside the end), the enlargement area signal outputs “1”, and the other target pixels are set to the edit area. When referring to the inside or outside of the frame, the stretched area signal outputs "0".

As described above, in the fourth embodiment, the stretched area generation unit 1501 assumes that the area in which the black line image, which is the boundary line, is to be expanded has a gap between the boundary line and the edit area of less than one pixel. Thus, a stretched area signal is generated by regarding the area as the first pixel outside the edge of the editing area.

In the fourth embodiment described above, it is assumed that the gap is smaller than one pixel. However, if the gap is two pixels or three pixels, the FIFO buffer 1
602 and FF1603, increase the filter size to 5 ×
If they are changed to 5 or 7 × 7, they can be handled respectively.

The detailed configuration of the spatial filter circuit 1210 according to the fourth embodiment will be described with reference to FIG. FIG.
12 is a diagram showing a detailed configuration of a spatial filter circuit 1210 shown in FIG.

The spatial filter circuit 1210 according to the fourth embodiment includes a 5 × 5 spatial filter 1402 composed of a FIFO buffer and a shift register group, and a 5 × 5 spatial filter 1402.
And a minimum value filter 1402.

Spatial filter 1401 and minimum value filter 1
Before 402, a selector 1403 that distributes an image signal to a spatial filter 1401 and a minimum filter 1402, and a selector 1404 that selects and outputs an image signal from one of the spatial filter 1401 and the minimum filter 1402.
Is provided.

The selectors 1403 and 1404 receive, as a select signal, a stretched area signal which is an output signal from the stretched area generator 1501, and determine which filter is to be used depending on the content of the stretched area signal. It is configured so that it can be switched.

When the stretched area signal is “0”, the input image passes through the spatial filter 1401 and is subjected to a predetermined process (through setting when no filter is used) and output. on the other hand,
When the stretched area signal is “1”, the input image passes through the minimum value filter 1402, performs a stretch process of a black line image as a boundary, and outputs an image.

FIG. 15 shows the minimum value filter 14 shown in FIG.
FIG. 2 is a diagram showing a detailed configuration of the second embodiment. In the fourth embodiment, the image signal input to the minimum filter 1402 is:
The four FIFO buffers 1901 extend the data to five lines delayed by one line and input to a 5 × 5 filter composed of 25 FFs 1902.

The output signals of the 25 F1902F are input to the minimum value determination circuit 1903. Minimum value judgment circuit 19
03 compares all the outputs of the 25 FFs 1902 and sets the smallest value as the output of the filter. That is, the minimum value filter 1402 of the fourth embodiment enlarges the black line image by setting the black image to be written in the enlargement area as the pixel having the lowest density in the filter window.

As described above, according to the fourth embodiment, when a process of designating an editing region by marker processing or the like and filling a region surrounded by a boundary line is performed, a fruit line image for which a boundary is determined in advance is used. Is stretched in the editing region direction, thereby eliminating the gap between the black line image and the filled image at the boundary portion, and suppressing white spots near the boundary.

In the above description, the case where one point is specified on the document by the marker has been described. However, when the specification is performed by the digitizer, the area generating circuit 212 uses the image data as the marker signal. Only the black data (boundary line) is stored in the memory, and the position on the document specified by the digitizer is then stored in the CPU 1 shown in FIG.
The same effect can be obtained by writing data to the corresponding position in the memory 1004 by 005 and thereafter performing the operation after data storage in the memory described above.

[Other Embodiments] Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus including a single device can be used. (For example, a copying machine, a facsimile machine, etc.).

Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

Examples of a storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and CD.
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowcharts described above.

[0122]

As described above, according to the present invention, a change in image quality near the boundary of an area when image processing is performed on an image in the area is reduced by performing edge enhancement processing on the boundary of the area. And high-quality image processing results can be provided.

In the case where the designated area is filled with a predetermined color or image, the edge of the boundary image is emphasized to reduce the color density of the gap between the boundary and the image in the area. The height can be increased to reduce white spots in the gap.

Further, according to the present invention, an area surrounded by a boundary line of a predetermined color is set as a designated area, and the image density of a predetermined color near the boundary line is increased so that the image at the boundary portion is processed by the image processing means. The gap between the image and the image can be narrowed, and the change in image quality near the boundary line can be reduced. In addition, even if a process of expanding the border image inward and stretching the border image inward is performed, the change in image quality near the border can be similarly reduced. It is possible to eliminate the gap between the processed image and the white spots near the boundary line and effectively suppress the gap.

[0125]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a color image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a detailed configuration of an image processing unit according to the embodiment.

FIG. 3 is a block diagram illustrating a detailed configuration of an edge detection unit illustrated in FIG. 2;

FIG. 4 is a diagram illustrating a detailed configuration of a luminance calculation circuit illustrated in FIG. 3;

FIG. 5 is a diagram for explaining a detailed configuration and operation of the edge minimum direction detection circuit shown in FIG. 4 including the edge detection filter unit according to the embodiment;

FIG. 6 is a diagram illustrating a detailed configuration of a spatial filter circuit illustrated in FIG. 2;

FIG. 7 is a block diagram illustrating a detailed configuration of an area signal generation circuit illustrated in FIG. 2;

FIG. 8 is a diagram for explaining the principle and effect of the edge enhancement processing according to the embodiment.

FIG. 9 is a diagram for explaining a detailed configuration of a spatial filter according to the second embodiment of the present invention.

FIG. 10 is a diagram showing a detailed configuration of a density correction circuit according to a third embodiment of the present invention;

FIG. 11 is a diagram showing an internal configuration of an image processing block 107 according to a fourth embodiment of the present invention.

FIG. 12 is a block diagram showing a detailed configuration of an area signal generation circuit shown in FIG. 11 in a fourth embodiment according to the present invention.

FIG. 13 is a diagram illustrating a detailed configuration of a stretched area generation unit illustrated in FIG. 6 according to a fourth embodiment;

14 is a diagram showing a detailed configuration of the spatial filter circuit shown in FIG.

FIG. 15 is a diagram illustrating a detailed configuration of a minimum value filter illustrated in FIG. 14;

FIG. 16 is a diagram illustrating a print result when a one-point instruction is performed on a document using a marker.

FIG. 17 is a diagram illustrating a print result when a loop instruction is given on a document using a marker.

FIG. 18 is a diagram illustrating a print result when a one-point instruction is performed on a document by a digitizer.

FIG. 19 is a diagram showing a printing result when a closed area is instructed on a document by a digitizer.

[Brief description of reference numerals]

 Reference Signs List 1 photosensitive drum 2 corona charger 3 laser exposure optical system 3a polygon mirror 3b lens 3c mirror 4y, 4c, 4m, 4Bk developing device 5 transfer device 5a transfer drum 5b transfer charger 5c adsorption charger 5d inner charger 5e outer charger 5f Recording material supporting sheet 5g Suction roller 5h Separation charger 5i Cam follower 6 Cleaning device 7a, b, c Recording material cassette 8a Separation claw 8b Separation push-up roller 9 Heat roller fixing device 10 Tray 11 Pre-exposure lamp 12 Potential sensor 13 Light quantity on drum Detecting means 14 Fur brush 15 Backup brush 16 Oil removing roller 19 Transport path switching guide 20 Transport vertical path 21a Reverse path 21b Reverse roller 22 Intermediate tray 24y, 24m, 24c, 24Bk Eccentric cam 25 Eccentric cam 27a, b, c Pick Up roller 30 Original 31 Original platen glass 32 Exposure lamp 33 Lens 34 Full color sensor (CCD) 35 Optical system reading drive motor 36 Image processing unit 37 Controller unit

Continued on front page F-term (reference) 5B057 AA11 BA02 BA24 BA26 CA01 CA06 CA08 CA12 CA16 CB01 CB06 CB08 CB12 CB16 CE03 CE05 CE06 CH01 CH08 CH11 CH18 DA08 DA17 DB02 DB06 DB08 DB09 DC16 5C076 AA27 AA31 AA32 AA40 MP06 CA07 CA07 CA07 MP08 PP02 PP03 PP19 PP27 PP28 PP38 PP43 PP47 PP58 PP68 PQ08 PQ12 PQ20 PQ22 RR02 RR14 RR18 RR19 RR21

Claims (21)

[Claims] 1. An area specifying means for specifying an area of a processed image, an edge emphasizing means for performing an edge emphasizing process on a boundary of the area specified by the area specifying means, and a boundary of the area emphasized by the edge emphasizing means An image processing apparatus comprising: image processing means for performing predetermined image processing on a processed image within the image processing apparatus; and reducing a change in image quality near a boundary. 2. The image processing apparatus according to claim 1, wherein the image processing unit performs a process of filling an area specified by the area specifying unit with a predetermined color or image. 3. The image processing apparatus according to claim 1, further comprising an instruction unit for instructing image processing, wherein the image processing unit performs the image processing only when the image processing is instructed by the instruction unit. An image processing device according to any one of the above. 4. The image processing apparatus according to claim 1, wherein the area designating unit sets a region surrounded by a boundary line of a predetermined color as a designated region, and the edge enhancing unit increases an image density of the predetermined color near the boundary line to increase an image at the boundary. 4. The image processing apparatus according to claim 1, wherein a gap between the image and the image processed by the image processing unit is narrowed to reduce a change in image quality near a boundary line. 5. The image processing according to claim 1, wherein said edge enhancement means is a process of expanding a boundary image inward and expanding the boundary image in an in-region direction. apparatus. 6. A first extracting means for extracting data for designating an image area from input image data, a second extracting means for extracting data serving as a boundary of the image area from the input image data, An emphasis means for emphasizing the edge of the data with respect to the color data corresponding to the color of the boundary line extracted by the second extraction means; and compressing the data specifying the image area extracted by the first extraction means. First compressing means for generating first compressed data, first storing means for storing the first compressed data, and compressing data output from the emphasizing means to generate second compressed data. Second compression means for generating; second storage means for storing the second compressed data; data stored in the first storage means;
An operation unit that performs an operation using the data stored in the storage unit, a third storage unit that stores an operation result of the operation unit, and a data stored in the third storage unit. Data decompression means for decompressing compressed data stored in the first storage means, a processing area determination means for determining a processing area from data decompressed by the data decompression means, An image processing apparatus comprising: an image processing unit that performs predetermined image processing according to a processing signal output from a processing area determination unit. 7. The image processing apparatus according to claim 6, further comprising instruction means for instructing image processing, wherein said image processing means performs image processing only when image processing is instructed by said instruction means. 8. A first extracting means for extracting data for designating an image editing area from input image data, and a second extracting means for extracting data serving as a boundary of the image editing area from the input image data. A density level conversion unit that replaces the data density of the color data corresponding to the color of the boundary line extracted by the second extraction unit with a high level; and an image editing area extracted by the first extraction unit. The first compressed data to generate the first compressed data.
Compression means; first storage means for storing the first compressed data; second compression means for compressing data output from the density level conversion means to generate second compressed data; A second storage unit that stores the second compressed data; a data storage unit that stores the data stored in the first storage unit;
An operation unit that performs an operation using the data stored in the storage unit, a third storage unit that stores an operation result of the operation unit, and a data stored in the third storage unit. Data decompression means for decompressing the compressed data stored in the first storage means, an area determination means for determining an image processing area based on the data decompressed by the data decompression means, An image processing apparatus comprising: an image processing unit that performs image processing according to a processing signal output from the area determination unit. 9. A first extracting means for extracting data for designating an image editing area from input image data, and a second extracting means for extracting data serving as a boundary line of the image editing area from the input image data. And a first step of compressing data specifying the image editing area extracted by the first extracting means to generate first compressed data.
Compression means; first storage means for storing the first compressed data; second compression means for compressing the data extracted by the second extraction means to generate second compressed data; A second storage unit that stores the second compressed data; an operation unit that performs an operation using the data stored in the first storage unit and the data stored in the second storage unit; Third storage means for storing the result of the calculation according to the above, data expansion means for expanding the data by referring to the data stored in the third storage means, and processing from the data expanded by the data expansion means. An area determining means for determining an area and outputting a processing signal; and an area signal for extending data from the processing area determined by the area determining means with respect to boundary line data extracted by the second extracting means. A stretched region generating means to be formed; a stretcher for performing data stretching processing on boundary line data extracted by a second extractor in accordance with a stretched region signal generated by the stretched region generator; and the input image data. Image processing means for performing image processing in accordance with a processing signal output from the area determination means. 10. An area specifying step of specifying an area of a processed image, an edge emphasizing step of performing an edge emphasizing process on a boundary of the area specified in the area specifying step, and a boundary of the area emphasized by the edge emphasizing step. An image processing step of performing predetermined image processing on a processed image in the image, and reducing a change in image quality near the boundary. 11. The image processing method according to claim 10, wherein, in the image processing step, a process of filling an area specified in the area specifying step with a predetermined color or image is performed. 12. The image processing apparatus according to claim 10, further comprising an instruction unit for instructing image processing, wherein the image processing step performs the image processing only when the image processing is instructed by the instruction unit. An image processing method according to any one of the above. 13. The region specifying step sets a region surrounded by a boundary line of a predetermined color as a specified region, and the edge emphasizing step increases an image density of the predetermined color near the boundary line to increase an image at a boundary portion. 2. The image processing method according to claim 1, wherein a gap between the image and the image processed in the image processing step is reduced to reduce a change in image quality near a boundary line.
3. The image processing method according to any one of 2. 14. The edge emphasizing process in the edge emphasizing step is a process of expanding a boundary line image inward and expanding the boundary line image in an in-region direction. The image processing method according to 1. 15. A first extraction step of extracting data for designating an image area from input image data, a second extraction step of extracting data serving as a boundary of the image area from the input image data, An emphasizing step of performing data edge emphasizing processing on the color data corresponding to the color of the boundary line extracted in the second extracting step; and compressing the data specifying the image area extracted in the first extracting step. A first compression step of generating first compressed data and storing the first compressed data in a first storage means; and compressing data output from the emphasizing step to generate second compressed data to generate a second storage A second compression step of storing the data in the first storage means;
An operation step of performing an operation using the data stored in the storage means, and storing a result in the third storage means; and referring to the data stored in the third storage means, the first storage A data decompression step of decompressing the compressed data stored in the means, a processing area determination step of determining a processing area from the data decompressed by the data decompression step and outputting a processing signal, An image processing step of performing predetermined image processing according to a processing signal output from the processing area determination step. 16. The image processing method according to claim 15, further comprising instruction means for instructing image processing, wherein said image processing step performs image processing only when image processing is instructed by said instruction means. 17. A first extraction step of extracting data for designating an image editing area from input image data, and a second extraction step of extracting data serving as a boundary of the image editing area from the input image data. A density level conversion step of replacing the data density of the color data corresponding to the color of the boundary line extracted in the second extraction step with a higher level; and specifying an image editing area extracted in the first extraction step. A first compression step of compressing data to be generated to generate first compressed data and storing the compressed data in a first storage means; A second compression step of storing the data in the second storage means, and the data stored in the first storage means and the second compression step.
An operation step of performing an operation using the data stored in the storage means, and storing the result in the third storage means; and the first storage means with reference to the data stored in the third storage means A data decompression step of decompressing the compressed data stored in the data decompression step; an area determination step of determining an image processing area based on the data decompressed in the data decompression step and outputting a processing signal; An image processing step of performing image processing according to a processing signal output from the area determination step. 18. A first extraction step of extracting data for designating an image editing area from input image data, and a second extraction step of extracting data serving as a boundary of the image editing area from the input image data. A first compression step of compressing data designating the image editing area extracted in the first extraction step to generate first compressed data and storing the first compressed data in a first storage unit; A second compression step of compressing the data extracted in the step to generate second compressed data and storing the generated data in a second storage unit; and storing the data stored in the first storage unit and the second storage unit. An operation step of performing an operation using the stored data and storing an operation result in a third storage unit; a data expansion step of expanding the data with reference to the data stored in the third storage unit; The data expansion step An area determining step of determining a processing area from the data decompressed and outputting a processing signal; and outputting data to the boundary line data extracted in the second extraction step from the processing area determined in the area determining step. A stretched area generating step of generating a stretched area signal and outputting a stretched area signal; and stretching the data with respect to the boundary line data extracted in the second extraction step by the stretched area signal generated in the stretched area generating step. An image processing apparatus comprising: a stretching step of performing processing; and an image processing step of performing image processing on the input image data according to a processing signal output from a region determination step. 19. The image processing apparatus according to claim 1, further comprising reading means for reading a document, wherein the input image is document image data read by the reading means. apparatus. 20. A computer program sequence for realizing the function according to any one of claims 1 to 19. 21. A computer-readable recording medium storing a computer program for realizing the functions according to any one of claims 1 to 19.