JP2014076624A - Preview image generation device, method and computer program for preview image generation - Google Patents

Abstract

A preview image useful for preview display before rasterization is completed is generated.
In a process in which a plurality of objects constituting an output image to be previewed are sequentially drawn on a memory area, each time one of the plurality of objects is drawn, the output image is drawn. The evaluation value of the quantitative evaluation for the area of the part and the visual information represented by the part is calculated, and when the area exceeds the area threshold and the evaluation value exceeds the information amount threshold, An image representing only the drawn object is generated as a preview image.
[Selection] Figure 10

Description

  The present invention relates to a technique for generating a preview image to be displayed for preview.

  There are image forming apparatuses and network printing systems that perform preview display of print results. This type of device or system performs rasterization (raster image processing) for drawing a print image on a memory when printing a document having non-raster data such as vector data or text data. Then, a raster image obtained by rasterization or an image (usually a reduced image) obtained by scaling it according to the display is displayed as a preview image. In the case of color printing, rasterization is performed for each color component of RGB or YMCK, and a color image obtained by synthesizing a raster image of each color component or a scaled image thereof is displayed as a preview image.

  Conventionally, preview display is performed after rasterization is completed. For this reason, the start time of the preview display depends on the time required for rasterization. The larger the number of objects to be drawn, such as characters, graphics, and photos, the longer the rasterization takes, and the start of preview display is delayed.

  Japanese Patent Application Laid-Open No. H10-228707 discloses a quick preview display in network printing. In the method disclosed in this document, when a preview is displayed on a host (personal computer) instructing printing to the printer, the printer rasterizes a part of the print image, and the host rasterizes the remaining part. Then, the rasterized results of both are combined and displayed by the host. According to this, as compared with the case where the entire print image is rasterized by the printer, the data amount of the print image to be transferred from the printer to the host is reduced, and the time required for transfer is shortened.

JP 2001-282499 A

  It is conceivable to start preview display in the middle of rasterization, not after rasterization is completed. For example, in complex rasterization involving transparent processing for overlapping objects, the required time may range from several tens of seconds to one minute depending on the processing capability of the apparatus. The preview display at an intermediate stage is useful for providing information to the user at an early stage.

  From the viewpoint of providing information at an early stage, preview display may be performed sequentially immediately after the start of rasterization. However, for the purpose of previewing, the user cannot confirm whether the original data being rasterized is exactly what the user specified, and may predict the completed state of the image being rasterized to some extent. The significance of providing information that cannot be done is small. In addition, in order to reduce the burden on the apparatus that performs processing for preview display, it is preferable to use as little resources as possible. In particular, when a rasterized image is reduced and displayed as a preview, it is not preferable to frequently update the preview display because resources corresponding to the reduction are used.

  In view of such circumstances, an object of the present invention is to generate a preview image that is useful when preview display is performed before rasterization is completed.

  An apparatus that achieves the above object is a preview image generation apparatus that generates a preview image to be displayed for previewing an output image, and generates the output image by sequentially drawing a plurality of objects on a memory area. In the process, each time one of the plurality of objects is drawn, an area calculating means for calculating the area of the drawn portion of the output image, and in the process, one of the plurality of objects is drawn. Each time, the evaluation value calculation means for calculating an evaluation value of quantitative evaluation for the visual information represented by the rendered portion of the output image, and the area calculated by the area calculation means exceeds an area threshold value. And when the evaluation value calculated by the evaluation value calculation means exceeds an information amount threshold, the plurality of objects An image representing only rendered objects out and an image generating means for generating as the preview image.

  According to the present invention, it is possible to generate a preview image useful for providing information when preview display is performed in the middle of rasterization in which a plurality of objects are sequentially drawn.

It is a figure which shows the structure of the network in which the preview display based on embodiment of this invention is performed. FIG. 2 is a diagram illustrating a schematic hardware configuration of an image forming apparatus having a function of generating a preview image. FIG. 3 is a diagram illustrating a functional configuration related to an operation as a preview image generation apparatus in the image forming apparatus. It is a figure which shows the example of the information for calculation used for calculation of the data amount as an evaluation value in connection with the production | generation of a preview image. It is a schematic diagram of the edge extraction in connection with calculation of data amount. It is a flowchart of the operation | movement which selects the information for calculation according to the size of a display. It is a figure which shows the threshold value table used for the determination with respect to the image in drawing used as the origin of a preview image. It is a figure which shows typically the several object drawn. It is a figure which shows the procedure of drawing using a some memory area. It is a figure which shows the 1st example of the production | generation operation | movement of the preview image according to the size of a display. It is a figure which shows the 2nd example of the production | generation operation | movement of the preview image according to the size of a display. It is a figure which shows the 3rd example of the production | generation operation | movement of the preview image according to the size of a display.

  Assume that a preview image is generated in an image forming apparatus used for network printing.

  An image forming apparatus 1 shown in FIG. 1 is an MFP (Multi-functional Peripheral) having various functions other than a printing function and printing. The image forming apparatus 1 is connected to a local area network (LAN) 2 having an access point 3 that enables wireless communication. The image forming apparatus 1 is given a copy job and a print job by direct operation from the operation panel 22, and is given a print job by access from an external device via the LAN 2.

  In the print job, a document given from an external device, a document stored in a box 305 in the image forming apparatus 1, or a document read from a removable memory 7 such as a USB memory is printed. When the preview mode is designated at the time of executing the print job, a preview image generated as described later is displayed on the operation panel 22 or the external device that has requested printing.

  External devices that request printing to the image forming apparatus 1 include personal computers (PCs) 5a and 5b connected to the LAN 2 by cables, and mobile devices 6a and 6b such as mobile phones and tablet computers that are accessed by wireless communication. . A cloud system 8 accessed via the Internet 4 connected to the LAN 2 is also included in the external device. These external devices send document data to be printed to the image forming apparatus 1 to request printing, or specify a document stored in the box 305 in advance to request printing.

  FIG. 2 shows a hardware configuration of the image forming apparatus 1. A main controller 10 responsible for overall control of the image forming apparatus 1 includes a CPU (Central Processing Unit) 11 as a computer for executing control programs and various applications, a ROM (Read Only Memory) 12 for storing control programs, and a program execution work. It has a RAM (Random Access Memory) 13 serving as an area, and a battery-backed NV-RAM (nonvolatile memory) 14 for storing setting data necessary for control.

  The operation panel 22 includes a display 225 that displays an operation screen. An ADF (Auto Document Feeder) 23 conveys a document sheet to a reading position in the image scanner 24 in copying, image input, or facsimile transmission. The image scanner 24 optically reads image information recorded on the document sheet. The printer engine 25 prints a monochrome or color image by electrophotography on one or both sides of the paper supplied from the multistage paper stacker 26.

  A modem 27 and an NCU (Network Control Unit) 28 are used for facsimile communication via a public telephone line. The communication interface 29 connects the image forming apparatus 1 to a network for communication with an external apparatus. The communication interface 29 includes a USB interface for connecting an external device including a removable memory.

  The storage 30 is a mass storage device such as a hard disk drive (HDD). The storage 30 is used as a medium for storing a control program and control data. The storage 30 is provided with a box 305 that is a memory area for storing various documents. Data and programs stored in the storage 30 are loaded into the work area as necessary.

  FIG. 3 shows a functional configuration related to generation of a preview image in the main controller 10. The main controller 10 includes a job management unit 101, a drawing unit 102, an area calculation unit 103, a data amount calculation unit 104, a drawing monitoring unit 105, and a preview image generation unit 106. These elements are functional elements realized by the CPU 11 executing a predetermined program. Among these elements, the drawing unit 102, the area calculation unit 103, the data amount calculation unit 104, the drawing monitoring unit 105, and the preview image generation unit 106 are functional elements that realize the operation as the preview image generation device 100. is there.

  The job management unit 101 sets a job to be executed in response to an instruction from the operation panel 22 or a request from the external device 8, and controls the progress of the job. The drawing unit 102 is a raster image processor (RIP) that draws a print image of each page of a document to be printed on a memory when a print job is executed. The drawing unit 102 secures a necessary number of memory areas 31, 32, 33, and 35 in the RAM 13 according to the document specified by the job management unit 101, and stores a plurality of objects constituting a print image as an output image. Draw in order. A raster image obtained by drawing (rasterization) is sent to the printer engine 25 and used for printing by an electrophotographic process.

  The preview image generation apparatus 100 generates a preview image based on a print image in the middle of drawing before drawing of a print image for one page by the drawing unit 102 is completed. In order not to generate a preview image that is meaningless for the user who performs the preview, the preview image generation device 100 generates a preview image when drawing has been performed to such an extent that it can be assumed that the information provided to the user is not meaningless. To do. Functional elements related to the determination of whether or not meaning is an area calculation unit 103, a data amount calculation unit 104, and a drawing monitoring unit 105.

  In the process in which a plurality of objects are sequentially drawn, the area calculation unit 103 is configured such that each time one of the plurality of objects is drawn, the area of the portion in which the object is drawn (the memory bit of the memory bit used for drawing) is drawn. Use amount). The area here corresponds to the area of the drawn portion of the print image. When calculating the area, if the objects partially overlap, the overlapping areas are not overlapped. The area value corresponding to the overlapping objects is smaller than the sum of the individual areas of these objects.

  The data amount calculation unit 104 is a means for calculating an evaluation value for quantitative evaluation with respect to visual information represented by a drawn portion of a print image. The data amount calculation unit 104 calculates a “data amount” as an evaluation value based on the calculation information every time one of a plurality of objects is drawn. In the present embodiment, the data amount is the total score for a plurality of image elements included in the portion. Image elements such as characters, image edges, and graphic outlines are selected in advance as candidates for components of visual information, and a score is determined for each of the assumed three display sizes for the selected image elements. A score table T1, T2, T3 for each display size indicating the score of each image element is stored in the storage 30 or the NV-RAM 14 as calculation information. The data amount calculation unit 104 loads at least one of the stored score tables T1, T2, and T3 into the RAM 13 before starting drawing, and refers to the score tables T1, T2, and T3 during drawing. Calculate the amount of data.

  The drawing monitoring unit 105 writes the area and data amount calculated by the area calculating unit 103 and the data amount calculating unit 104 in the drawing monitoring table T5. The drawing monitoring unit 105 records the area and data amount for each memory area for drawing, and the area and data amount in the drawing monitoring table T5 each time an object is drawn in any of the memory areas 31, 32, 33, and 35. Is updated, and the total area and the total data amount of all the memory areas 31, 32, 33, and 35 used for drawing are calculated. Then, the drawing monitoring unit 105 compares the total area with the area threshold indicated by the threshold table Tth, and compares the total data amount with a similar data amount threshold. When the total area exceeds the area threshold and the total data amount exceeds the data amount threshold, the drawing monitoring unit 105 notifies the preview image generation unit 106 to that effect.

  The preview image generation unit 106 receives the notification from the drawing monitoring unit 105 and generates a preview image. That is, a raster image drawn from the memory areas 31, 32, 33, and 35 is read, a plurality of read raster images are combined, and the obtained combined image is scaled to fit the display size to obtain a preview image. Finalize.

  The generated preview image is used for preview display. When a job is designated by the operation panel 22, the preview image is delivered to the panel display control unit 107 that controls display on the operation panel 22. When a job is designated by access from an external device, the preview image is delivered to the communication control unit 107 that is responsible for communication with the external device.

  4A, 4B, and 4C show examples of the score tables T1, T2, and T3 referred to by the data amount calculation unit 104. FIG. The score table T1 is a table for a PC size (large size) assuming preview display on a display having a screen size of 13 inches or more. The score table T2 is a table for a tablet terminal size (medium size) assuming a preview display on a display having a screen size of 7 inches or more and less than 13 inches. The score table T3 is a table for portable terminal size (small size) assuming preview display on a display having a screen size of less than 7 inches.

  In the score tables T1, T2, and T3, the objects are roughly classified into three types: “raster image”, “figure”, and “character string”. For example, a photograph corresponds to a raster image, and a graph corresponds to a figure. For the “raster image” of the object type, “edge” is selected as one of the image elements, and the score of the edge per unit length is determined by conversion in the size drawn in the memory area. The edge is a boundary line between portions where the difference in density in the raster image is clear. In FIG. 5, an edge 590 is extracted from the object 59 (raster image). For the “graphic” object type, “contour” is selected as one of the image elements, and the score of the contour per unit length is determined by the same conversion as described above. For the “character string” of the object type, “character” is selected as one of the image elements, and the score for each character size is shown.

  For example, when paying attention to the “character string” of the object type, the score increases by 3 points each time the character size increases by 1 pt (1 point) in the large size score table T1. On the other hand, in the score table T2 for medium size, only two points are increased, and in the score table T3 for small size, only one point is increased. That is, weighting is performed to increase the score as the screen size increases. The reason is that the smaller the screen size, the smaller the characters in the preview display and the lower the visibility of the characters. In the illustrated example, the same weighting is applied to “raster images” and “graphics” of other object types.

  As described in the flowchart shown in FIG. 6, the data amount calculation unit 104 selects one of the score tables T1, T2, and T3 as information to be referenced according to the screen size of the display that displays the preview (# 11). ~ # 14).

  FIG. 7 shows an example of the threshold table Tth referred to by the drawing monitoring unit 105. In the threshold value table Tth, an area threshold value and a data amount threshold value (score threshold value) are defined for three screen sizes. In the example, a common area threshold value and a common data amount threshold value (score threshold value) correspond to the PC size (large size) and the tablet terminal size (medium size). The unit of the area threshold is the ratio (%) of the drawn part of the object to the entire print image to be drawn (drawing area for one page).

  In FIG. 7, the area threshold value of the mobile terminal size is 90%, which is larger than the area threshold values (70%) of the PC size and the tablet terminal size. This means that with regard to the size of the mobile terminal, the drawing area is more important in the evaluation of visual information than other sizes. The reason why the drawing area is emphasized is that, as described above, there is a possibility that it becomes difficult to identify details in the small-size preview display, and it is considered that the user pays attention to the overall aspect of the screen.

  Hereinafter, functions and operations of the preview image generating apparatus 100 will be described by taking as an example the case where the six objects 51, 52, 53, 54, 55, and 56 shown in FIG. 8 are drawn.

  In FIG. 8, objects 51, 52, 53, 54, 55, and 56 correspond to the six layers (layer 1 to layer 6) in the multi-layer image one by one in order. The object 51 corresponding to the lowest layer 1 has a size over almost the whole area except the peripheral portion of the drawing area 40 for one page. The object 51 is, for example, a background image. Other objects 52 to 56 that are smaller than the object 51 are respectively drawn at predetermined positions in the drawing area 40. Objects 54 and 56 contain relatively large characters.

  These six objects 51 to 56 are basically drawn in the order of layer arrangement from the bottom layer. However, in this example, the objects 52 and 53 are transparent objects, and the pixel value is such that the lower layer can be seen through the image in which the layer 53 object 53 is superimposed on the layer 2 object 52. It is necessary to add transparency processing to change Similarly, the objects 55 and 56 are also transparent objects, and it is necessary to apply the same transparent process to an image obtained by superimposing the object 56 on the object 55. In other words, simple drawing in which a single memory area is used to overwrite the layers in the order in which layers are arranged cannot achieve the printing required by the job. Therefore, six objects 51 to 56 are drawn using the three memory areas 31, 32, and 33 as shown in FIG.

In FIG. 9, the drawing process of objects 51, 52, 53, 54, 55, and 56 has eight states (state 1 to state 8). The processing in each state is as follows.
[State 1] The object 51 is drawn using the first memory area 31, and an image 41 is obtained.
[State 2] The object 52 is drawn using the second memory area 32, and an image 42 is obtained.
[State 3] An object 53 is drawn on the image 42 in the second memory area 32 in an overwriting format to obtain an image 43.
[State 4] An object 54 is drawn on the image 41 in the first memory area 31 in an overwrite format to obtain an image 44.
[State 5] The object 55 is drawn using the third memory area 33, and an image 45 is obtained.
[State 6] An object 56 is drawn on the image 45 in the third memory area 33 in an overwrite format to obtain an image 46.
[State 7] The image 46 on the third memory area 33 is superimposed on the image 43 on the second memory area 32, and an image 47 is obtained by performing a transparent process.
[State 8] The image 47 on the second memory area 32 is superimposed on the image 44 on the first memory area 31 and subjected to a transparent process to obtain an image 48 as a print image to be drawn required by the job.

  FIG. 10 shows a first example of preview image generation operation. “Memory (1)”, “Memory (2)”, and “Memory (3)” described in the drawing monitoring table T5 in the drawing are a first memory area 31, a second memory area 32, and a third memory, respectively. The memory area 33 is indicated. The same applies to FIGS. 11 and 12 described later.

  In the first example shown in FIG. 10, a print job involving drawing of the objects 51 to 56 is given to the image forming apparatus 1 by a direct operation using the operation panel 22, and a preview display is performed on the display 225 of the operation panel 22. . Since the screen size of the display 225 is the tablet terminal size (medium size), the score table T2 is used for calculating the data amount.

  In state 1 of the drawing process, in response to the drawing of the object 51 in the first memory area 31, the data of the drawing monitoring table T5 is updated. At the time of the update, the area calculated for the first memory area 31 is 90%, for example, and the data amount is 320 points. Since no objects are drawn in the second memory area 32 and the third memory area 33, the area for these is 0% and the amount of data is 0 points. Therefore, the total area for the three memory areas 31 to 33 is 90%, and the total data amount is 320 points.

  In the state 1 stage, the total area (here 90%) exceeds the area threshold (70%) corresponding to the tablet terminal size. However, the total amount of data (320 points) does not exceed the data amount threshold (1000 points) corresponding to the tablet terminal size. Accordingly, no preview image is generated at this stage.

  In state 2, in response to the drawing of the object 52 in the second memory area 32, the data in the drawing monitoring table T5 is updated. At the time of the update, the area calculated for the second memory area 32 is, for example, 30%, and the data amount is also 200 points. The drawing range of the object 52 is included in the drawing range of the object 51 when the image 42 having the object 52 is superimposed on the image 41 having the object 51 drawn earlier. Therefore, the total area for the three memory areas 31 to 33 is 90%, which is the same as the value in the state 1 stage. On the other hand, the total data amount is the sum of the data amount for the first memory area 31 (320 points) and the data amount for the second memory area 32 (200 points), that is, 520 points. Even in the state 2 stage, the total amount of data (520 points) does not exceed the data amount threshold (1000 points) corresponding to the tablet terminal size.

  In the same procedure, the data in the drawing monitoring table T5 is updated each time the objects 53, 54, and 55 are drawn in order in the state 3 to the state 5.

  Thereafter, in state 6, the total amount of data for the three memory areas 31 to 33 is 1060 points, which is greater than the data amount threshold. Since the total area already exceeds the area threshold at the stage of state 1, the condition for preview display at the stage of state 6 is satisfied. Therefore, a preview image representing the object that has been drawn at the present time is generated.

  The preview image generation unit 106 (see FIG. 3) selects a set number of selected items in descending order of the calculated data amount in the three memory areas 31, 32, and 33 used for drawing in order to reduce the load on the CPU 11. An image representing only the object drawn in the memory area is generated as a preview image. For example, if the set number is 2, the first memory area 31 and the third memory area 33 are selected in FIG. Then, the image 44 in the first memory area 31 and the image 46 in the third memory area 33 are combined and scaled to fit the display 225 to generate a preview image 60M as shown. The generated preview image 60M is displayed on the display 225 of the operation panel 22.

  Even when preview display is performed in an external device having a display having the same screen size as the display 225 of the operation panel 22 such as a tablet or a small notebook PC, the preview image 60M is generated as shown in FIG.

  FIG. 11 shows a second example of the preview image generation operation. In this second example, a print job involving drawing of the objects 51 to 56 is given to the image forming apparatus 1 by access from the external apparatus, and preview display is performed on a PC size (large size) display provided in the external apparatus. A PC size score table T1 is used to calculate the data amount.

  Similar to the first example described above, each time the objects 51 to 56 are drawn, the data in the drawing monitoring table T5 is updated. In the state 1 stage, the total area (90%) is equal to or larger than the PC size area threshold (70%), but the total data volume (480 points) is smaller than the PC size data volume threshold (1000 points).

  When drawing has progressed to state 4, the total amount of data (1140 points) is equal to or greater than the data amount threshold. Since the total area has already exceeded the area threshold value at the stage of state 1, a preview image is generated at the stage of state 4.

  The preview image generation unit 106 selects the first memory area 31 having the largest data amount and the second memory area 32 having the second largest amount of data among the three memory areas 31, 32, and 33, and selects these memory areas 31. , 32. Then, the preview image generation unit 106 combines the image 44 in the first memory area 31 and the image 43 in the second memory area 32, scales the image to fit the display, and displays a preview image 60L as illustrated. Is generated. The generated preview image 60L is displayed on an external device (the personal computer 5a in the drawing).

  FIG. 12 shows a third example of the preview image generation operation. In this third example, a print job involving drawing of the objects 51 to 56 is given to the image forming apparatus 1 by access from a small external device such as a smartphone or a mobile phone, and the mobile terminal size (small size) provided in the external apparatus is provided. ) Displays a preview. For the calculation of the data amount, a score table T3 for the portable terminal size is used.

  As in the first and second examples described above, the data in the drawing monitoring table T5 is updated each time the objects 51 to 56 are drawn. In the state 1 stage, the total area (90%) is equal to or larger than the mobile terminal size area threshold (90%), but the total data amount (160 points) is larger than the mobile terminal size data amount threshold (300 points). Few.

  At the stage where drawing has progressed to state 3, the total amount of data (300 points) is equal to or greater than the data amount threshold. Since the total area has already exceeded the area threshold at the stage of state 1, a preview image is generated at the stage of state 3.

  The preview image generation unit 106 selects the first memory area 31 having the largest data amount and the second memory area 32 having the second largest amount of data among the three memory areas 31, 32, and 33, and selects these memory areas 31. , 32. Then, the preview image generation unit 106 synthesizes the image 41 in the first memory area 31 and the image 43 in the second memory area 32, scales the image to fit the display, and displays a preview image 60S as illustrated. Is generated. The generated preview image 60L is displayed on an external device (in the figure, the portable device 6a).

  According to the above embodiment, the preview images 60L, 60M, and 60S having visual information corresponding to the screen size of the display used for the preview display are generated, and the practicality of the preview in various devices having different screen sizes can be improved. it can.

  In the above-described embodiment, after the preview images 60L, 60M, and 60S are generated in the middle of the drawing specified by the job, the preview image is periodically generated in parallel with the progress of drawing so that the preview display can be updated. May be. After the preview images 60L, 60M, and 60S are generated in the middle of drawing, the preview image corresponding to the completed print image may be generated after the drawing is completed. In the process of drawing one page, a new preview image may not be generated after the preview images 60L, 60M, and 60S are generated in the middle.

  As the data amount, the total of the drawing areas of the objects drawn in each memory area may be calculated. In this case, the areas are overlapped and added for a part where a plurality of objects partially or entirely overlap.

  Regarding characters, it is considered that the amount of information recognized by the user is larger than other image elements, and the score may be given higher weight.

  The number of memory areas to be selected when the preview images 60L, 60M, and 60S are generated is not limited to 2 illustrated. It may be 1 or 3 or more. Images may be taken from all the memory areas used for drawing without being selected and combined. If there are more memory areas with the same amount of data than the set number, the memory areas may be selected according to the order determined in advance in each memory area, and the subsequent image processing is simpler such that fine line processing is unnecessary. You may make it choose. A more appropriate one can be selected in consideration of the size of the area. You may make it select instead of the amount of data in order with a large area.

  If data specifying the screen size of the external device cannot be obtained in communication with the external device, one of the three score tables T1, T2, T3 determined in advance (for example, a large size score table T1) ) Can be used to calculate the amount of data.

  When the screen size of the display for preview display is fixed, only a single score table suitable for the screen size is provided, and a process for selecting one to be applied from the plurality of score tables T1, T2, T3 Can be omitted.

100 Preview Image Generation Device 11 CPU (Computer)
60L, 60M, 60S Preview image 51, 52, 53, 54, 55, 56 Object 31, 32, 33 Memory area 103 Area calculation unit (area calculation means)
104 Data amount calculation unit (evaluation value calculation means)
106 Preview image generation unit (image generation means)
T1, T2, T3 Score table (table)

Claims (13)

A preview image generation device that generates a preview image displayed for previewing an output image,
In the process of generating the output image by sequentially drawing a plurality of objects on a memory area, each time one of the plurality of objects is drawn, the area of the drawn portion of the output image is calculated. An area calculating means to
In the process, each time one of the plurality of objects is drawn, an evaluation value calculation unit that calculates an evaluation value of quantitative evaluation for visual information represented by the drawn portion of the output image;
The drawn object of the plurality of objects when the area calculated by the area calculating unit exceeds an area threshold value and the evaluation value calculated by the evaluation value calculating unit exceeds an information amount threshold value An image generation means for generating an image representing only the image as the preview image. In the process, when a plurality of memory areas including the memory area are used for drawing the plurality of objects,
The area calculating means, for each time one of the plurality of objects is drawn in one of the plurality of memory areas, at least the memory area in which the object is newly drawn out of the plurality of memory areas. To calculate
The evaluation value calculation means, for each of any of the plurality of objects drawn in any of the plurality of memory areas, for at least a memory area in which the object is newly drawn out of the plurality of memory areas. Calculate the evaluation value,
The image generation means calculates the sum of the areas calculated by the area calculation means for each of the plurality of memory areas equal to or larger than the area threshold, and calculates the evaluation value calculation means for each of the plurality of memory areas. An image representing only an object drawn on the plurality of memory areas among the plurality of objects is generated as the preview image when a total of the evaluated values that are equal to or greater than the information amount threshold value. The preview image generating apparatus according to 1. 3. The image generation unit generates, as the preview image, an image representing only objects drawn in a set number of memory areas selected in descending order of the evaluation value among the plurality of memory areas. Preview image generation apparatus. The evaluation value calculating means calculates the total score of a plurality of image elements existing in the portion based on calculation information for determining a score for each image element selected in advance as a candidate of the visual information component The preview image generation device according to claim 1, wherein the preview image generation device is calculated as follows. The calculation information is a plurality of tables for each screen size that associates image elements with scores.
The preview image generation apparatus according to claim 4, wherein the evaluation value calculation unit calculates the evaluation value based on a table corresponding to a screen size of a display used for the preview display among the plurality of tables. A preview image generation method for generating a preview image to be displayed for output image preview,
In the process of generating the output image by sequentially drawing a plurality of objects on a memory area, each time one of the plurality of objects is drawn, the area of the drawn portion of the output image is calculated. And calculating an evaluation value of the quantitative evaluation for the visual information represented by the part,
When the calculated area is equal to or greater than an area threshold value and the calculated evaluation value is equal to or greater than an information amount threshold value, an image representing only a drawn object among the plurality of objects is used as the preview image. A preview image generation method characterized by generating the preview image. In the process, when a plurality of memory areas including the memory area are used for drawing a plurality of objects,
For each of the plurality of memory areas, calculate the area and the evaluation value,
When the sum of the areas calculated for each of the plurality of memory areas is greater than or equal to the area threshold, and the sum of the evaluation values calculated for each of the plurality of memory areas is greater than or equal to the information amount threshold. The preview image generation method according to claim 6, wherein an image representing only an object drawn in the plurality of memory areas among the plurality of objects is generated as the preview image. The selected memory areas are selected in descending order of the evaluation value from the plurality of memory areas, and an image representing only an object drawn in the selected memory area is generated as the preview image. Preview image generation method. 7. The total score of a plurality of image elements existing in the portion is calculated as the evaluation value based on calculation information for determining a score for each image element selected in advance as a candidate of the visual information component. 9. The preview image generation method according to any one of 8. As the calculation information, a plurality of tables for each screen size for associating image elements with scores are prepared,
The preview image generation method according to claim 9, wherein the evaluation value is calculated based on a table corresponding to a screen size of a display used for the preview display. In the calculation information, for at least characters of image elements, a score in a table corresponding to a large display screen size among the plurality of tables is larger than a score in a table corresponding to a small display screen size. The preview image generation method according to 10. The preview image generation method according to claim 11, wherein, in each of the plurality of tables, the score for a character increases as the character size increases. A computer program executed in an apparatus for generating a preview image displayed for previewing an output image,
To the computer that the device has,
In the process of generating the output image by sequentially drawing a plurality of objects on a memory area, each time one of the plurality of objects is drawn, the area of the drawn portion of the output image is calculated. Processing to
In the process, each time one of the plurality of objects is drawn, a process of calculating an evaluation value of quantitative evaluation for the visual information represented by the drawn portion of the output image;
When the calculated area is equal to or greater than an area threshold value and the calculated evaluation value is equal to or greater than an information amount threshold value, an image representing only a drawn object among the plurality of objects is used as the preview image. A computer program characterized by causing a process to be generated to be executed.

Images