TWI460679B - Section length enhancement unit and method - Google Patents

Description

Section length enhancement unit and method

The present invention relates to a unit and method, and more particularly to a section length enhancement unit and method.

Generally, the conventional image enhancement method is generally a global image enhancement, and the disadvantage is that the regional image details cannot be effectively enhanced.

As shown in Fig. 1, "RC Gonzalez and REWoods, Digital image processing, 3rd ed. Upper Saddle River, NJ: Prentice Hall, 2008." refers to a conventional spatial filtering that can perform regional image enhancement (Spatial). Filtering) image enhancement method, which is suitable for receiving an original picture with multiple pixels, and using different kernel masks to enhance the original picture according to user requirements, to obtain an enhanced picture, and The following steps:

Step A1: Select a suitable core mask according to user requirements. The core mask can be implemented by a certain filter, such as Low-Poss Filter, High-Pass Filter, and average. Filter (Mean Filter) and Sort Filter.

Step A2: performing a convolution operation on all pixel values f ( x, y ) of the original image by using the value w ( x, y ) of the selected core mask to obtain the enhanced picture, the enhanced picture having multiple Enhance the pixel value g ( x, y ) as shown in equation (1): g ( x, y ) = f ( x, y ) * w ( x, y ) (1)

The above formula (1) is a representation of a continuous format in which the gyro product becomes g _i,j = f _i,j * w _i,j , the parameters g _i,j , f _i,j , w _{i , j is} defined as the enhancement pixel value, the pixel value of the original image, the value of the core mask, and w _{i, j} can be regarded as a weight mask.

As shown in FIG. 2, the original picture displayed by the plurality of objects, and the enhanced picture obtained by the original picture through the spatial filtering image enhancement method is as shown in FIG. 3, and the object indicated by the arrow R in FIG. 3 can be seen. The adjacent boundary between the two is relatively blurred, and the internal texture of the object indicated by the arrow G is unclear.

The disadvantages of the conventional spatial filtering image enhancement method are:

1. The boundary of each object after image enhancement is blurred, and the internal texture is unclear.

2. The size of the core mask is different and corresponding to different image enhancement effects, so as the size of the core mask changes, the important image boundary information is blurred, that is, when the core mask size is larger, the blur The situation of important border information is more serious.

Accordingly, a first object of the present invention is to provide a segment length enhancement unit that can solve the above problems.

The segment length enhancement unit comprises: an enhancement value operation module, receiving an original picture having a plurality of pixels, and graying out all the pixels on the cutting line passing through the plurality of pixels in a predetermined range according to each pixel a step value, which is compared to obtain a maximum enhancement value and a minimum enhancement value; and a contrast enhancement module that receives each pixel of the original picture and receives the maximum corresponding to each pixel from the enhancement value operation module Enhanced value and The minimum enhancement value is used to enhance the contrast between the pixels to obtain an image enhancement picture.

A second object of the present invention is to provide a segment length enhancement method.

The segment length enhancement method is applicable to a segment length enhancement unit, the segment length enhancement unit includes an enhancement value operation module and a contrast enhancement module, and the segment length enhancement method includes the following steps: (A Using the enhanced value computing module to receive an original picture having a plurality of pixels, and comparing the grayscale values of all the pixels on the cutting line that are passed in a plurality of directions within a predetermined range for each pixel to obtain a a maximum enhancement value and a minimum enhancement value; and (B) receiving, by the contrast enhancement module, each pixel of the original picture, and receiving, from the enhancement value operation module, the maximum enhancement value and minimum enhancement corresponding to each pixel Values, and accordingly enhance the contrast between the pixels to obtain an image enhancement picture.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

As shown in FIG. 4, a preferred embodiment of the run length enhancement unit 3 of the present invention is adapted to be coupled to a display module 6 and receive a plurality of pixels having different coordinates (x, y). The original picture is enhanced, and the contrast between the pixels is enhanced to obtain an image enhancement picture, and includes: an enhancement value calculation module 4, and a contrast enhancement module 5.

The enhancement value computing module 4 includes a directional feature operator 41 and a feature comparator 42.

The contrast enhancement module 5 includes an averaging operator 51 and a contrast enhancer 52.

As shown in FIG. 5, the section length enhancement unit 3 performs a section length enhancement method, which includes the following steps:

Step 1: using the enhanced value computing module 4 to receive a plurality of pixels of the original picture, and performing grayscale values c _hk of all pixels on a cutting line that passes through a plurality of directions in a predetermined range according to each pixel. The comparison is to obtain a maximum enhancement value max _c and a minimum enhancement value min _c , as shown in equations (1) and (2), respectively:

Wherein, the parameter L is defined as the total number of cutting lines -1, as shown in FIG. 6, in this embodiment, the cutting lines of 8 directions (L=7) are respectively passed through the pixel fc (x, y) at the center coordinate. ) of _{l 0, l 1, ...,} l 7, l _h and the angle of each X-axis 22.5 × h °, should the size of the predetermined range of pixels k × k, k 3, and the coordinates of each pixel are the central coordinates of the preset range, but are not limited to this preset, and may also be other preset manners.

Again, step 1 includes the following sub-steps:

Sub-step 11: using the directional feature operator 41 to preset each pixel as a pixel of a central coordinate of the preset range, and perform averaging operations according to grayscale values of all pixels on the plurality of cutting lines passing through the center coordinate, respectively. Obtain an average grayscale value corresponding to each cutting line ~ .

Sub-step 12: using the feature comparator 42 to receive a plurality of average grayscale values corresponding to each pixel from the directional feature operator 41, and compare the average grayscale values to obtain one of the largest ones. The smallest one is the maximum enhancement value max _c and the minimum enhancement value min _c corresponding to each pixel.

Step 2: The contrast enhancement module 5 receives each pixel of the original picture, and receives the maximum enhancement value max _c and the minimum enhancement value min _c corresponding to each pixel from the enhancement value calculation module 4, and according to The image enhancement screen is obtained for comparison by the contrast to enhance the contrast between the pixels.

Again, step 2 includes the following substeps:

Sub-step 21: receiving, by the averaging operator 51, each pixel of the original picture, and taking each pixel as a pixel of a central coordinate of the preset range, and averaging grayscale values of all pixels in the preset range An operation is performed to obtain a critical value corresponding to each pixel of the original picture.

Sub-step 22: receiving, by the contrast enhancer 52, each pixel of the original picture, and receiving, from the feature comparator 42 the maximum enhancement value max _c and the minimum enhancement value min _c corresponding to each pixel, from the average operation Receiving the threshold value corresponding to each pixel, and comparing the grayscale values f(x, y) of the pixels to the corresponding threshold value respectively, and if the threshold value is greater than the corresponding threshold value, the gray of the pixel The order value is assigned to the maximum enhancement value max _c , and conversely, the gray scale value of the pixel is assigned to the minimum enhancement value min _c to obtain the image enhancement picture.

It should be noted that the above embodiment can be implemented by using hardware instead of software.

<Experimental results>

As shown in FIG. 7 , the image enhancement screen obtained after the original screen of FIG. 2 is processed by the section length enhancement unit 3 described above can be seen by comparing FIG. 7 with FIG. 3 : the object indicated by the arrow R of FIG. 7 . The adjacent boundary between the two is more obvious, and the internal texture of the object indicated by the arrow G is enhanced.

In summary, the above embodiment has the following advantages:

1. The boundary of each object after image enhancement is more obvious, and the internal texture contrast is enhanced.

2. Using directional regional image enhancement technology, it will not obscure important image boundary information due to changes in core mask size.

3. A region-enhanced image enhancement screen can be obtained, which can effectively enhance the contrast between pixels, and has the effect of removing noise and achieving the effect of disconnection.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1~2‧‧‧Enhanced steps

11~12‧‧‧Compare steps

21~22‧‧‧Steps for comparison

R, G‧‧‧ arrows

3‧‧‧ Section length enhancement unit

4‧‧‧Enhanced Value Computing Module

41‧‧‧ Directional Feature Operator

42‧‧‧Character Comparator

5‧‧‧Contrast Enhancement Module

51‧‧‧Average Operator

52‧‧‧Contrast enhancer

6‧‧‧Display module

1 is a flow chart of a conventional spatial filtering image enhancement method; FIG. 2 is an original picture; 3 is a block diagram of the original picture obtained by the spatial filtering image enhancement method; FIG. 4 is a block diagram of a preferred embodiment of the segment length enhancement unit of the present invention; FIG. 5 is a block diagram of the preferred embodiment. A flowchart of the length enhancement method; FIG. 6 is a schematic diagram showing eight cutting lines; and FIG. 7 is an image enhancement screen related to the original image.

3‧‧‧ Section length enhancement unit

4‧‧‧Enhanced Value Computing Module

41‧‧‧ Directional Feature Operator

42‧‧‧Character Comparator

5‧‧‧Contrast Enhancement Module

51‧‧‧Average Operator

52‧‧‧Contrast enhancer

6‧‧‧Display module

Claims (8)

A segment length enhancement unit includes: an enhancement value operation module that receives an original picture having a plurality of pixels and grays out all pixels on a cutting line that passes through a plurality of directions in a predetermined range for each pixel a step value, which is compared to obtain a maximum enhancement value and a minimum enhancement value; and a contrast enhancement module that receives each pixel of the original picture and receives the maximum corresponding to each pixel from the enhancement value operation module An enhancement value and the minimum enhancement value, and thereby enhancing the contrast between the pixels to obtain an image enhancement picture, the contrast enhancement module comprising: an averaging operator, receiving each pixel of the original picture, and each The pixel is a pixel of a central coordinate of the preset range, and averaging gray scale values of all pixels in the preset range to obtain a threshold corresponding to each pixel of the original picture; and a contrast enhancer Receiving each pixel of the original picture, and receiving, from the enhanced value operation module, the maximum enhancement value and the minimum enhancement value corresponding to each pixel, from the average operation Receiving the threshold value corresponding to each pixel, and comparing the grayscale values of the pixels to the corresponding threshold value respectively, and if greater than the corresponding threshold value, assigning the grayscale value of the pixel to the maximum enhancement The value, otherwise, assigns the grayscale value of the pixel to the minimum enhancement value to obtain the image enhancement picture. The segment length enhancement unit of claim 1, wherein the enhancement value calculation module comprises: a directional feature operator, each pixel is preset to the preset range a pixel of the center coordinate, and performing an average operation on the gray scale values of all the pixels on the plurality of cutting lines passing through the center coordinate to obtain an average gray scale value corresponding to each cutting line; and a feature comparator from the The directional feature operator receives a plurality of average grayscale values corresponding to each pixel, and compares the average grayscale values to obtain the largest one and the smallest one as the maximum corresponding to each pixel The enhancement value and the minimum enhancement value. The segment length enhancement unit according to claim 1, wherein the enhancement value operation module obtains the maximum enhancement value corresponding to each pixel according to the following manner: The parameters L, k, and c _hk are the total number of cut lines -1, the number of pixels, and the gray scale value of the pixel. The segment length enhancement unit according to claim 1, wherein the enhancement value calculation module obtains the minimum enhancement value corresponding to each pixel according to the following manner: The parameters L, k, and c _hk are the total number of cut lines -1, the number of pixels, and the gray scale value of the pixel. A segment length enhancement method, which is suitable for being executed by a segment length enhancement unit, the segment length enhancement unit includes an enhancement value operation module and a The contrast enhancement module includes an averaging operator and a contrast enhancer. The segment length enhancement method includes the following steps: (A) receiving an original image having a plurality of pixels by using the enhanced value computing module And comparing the grayscale values of all the pixels on the cutting line that each pixel passes through in a plurality of directions within a predetermined range to obtain a maximum enhancement value and a minimum enhancement value; and (B) using the contrast enhancement The module receives each pixel of the original picture, and receives the maximum enhancement value and the minimum enhancement value corresponding to each pixel from the enhancement value operation module, and accordingly enhances the contrast between the pixels to obtain an image enhancement. Screen, the step (B) includes the following sub-steps: (B1) receiving, by the averaging operator, each pixel of the original picture, and taking each pixel as a pixel of a central coordinate of the preset range, and the preset The grayscale values of all pixels in the range are averaged to obtain a threshold corresponding to each pixel of the original picture; and (B2) each image of the original picture is received by the contrast enhancer Receiving, from the enhanced value computing module, the maximum enhancement value and the minimum enhancement value corresponding to each pixel, receiving the threshold corresponding to each pixel from the averaging operator, and setting the grayscale of the pixels The value is respectively compared with the corresponding threshold value, and if it is greater than the corresponding threshold value, the grayscale value of the pixel is assigned as the maximum enhancement value, and vice versa, the grayscale value of the pixel is assigned as the minimum enhancement value. To obtain the image enhancement screen. The segment length enhancement method according to claim 5, wherein the enhancement value calculation module comprises a directional feature operator and a feature comparator, and the step (A) comprises the following substeps: (A1) using the directional feature operator to preset each pixel as a pixel of a central coordinate of the preset range, and performing averaging operations according to grayscale values of all pixels on the plurality of cutting lines passing through the center coordinate to obtain each An average grayscale value corresponding to a cutting line; and (A2) receiving, by the characteristic comparator, a plurality of average grayscale values corresponding to each pixel from the directional component operator, and performing the average grayscale values The comparison is to obtain the largest one and the smallest one as the maximum enhancement value and the minimum enhancement value corresponding to each pixel. The segment length enhancement method according to claim 5, wherein in the step (A), the maximum enhancement value corresponding to each pixel is obtained according to the following manner: The parameters L, k, and c _hk are the total number of cut lines -1, the number of pixels, and the gray scale value of the pixel. The segment length enhancement method according to claim 5, wherein in the step (A), the minimum enhancement value corresponding to each pixel is obtained according to the following manner: The parameters L, k, and c _hk are the total number of cut lines -1, the number of pixels, and the gray scale value of the pixel.