CN102193819B - Single-point noise resistant method and device for positioning light spot center - Google Patents

Abstract

The invention discloses a method for locating the spot center against single-point noise, which includes: sequentially comparing the gray value of each pixel of the spot image with a preset threshold, determining that pixels smaller than the threshold are marked as background pixels, and determining pixels larger than the threshold pixel, judge whether its adjacent pixel is a background pixel, if so, mark the current pixel as a noise pixel, otherwise, mark the current spot pixel according to the mark of the adjacent pixel of the current pixel; according to the mark of the adjacent pixel, perform Accumulate and store the centroid parameter group value, and do not accumulate and store the centroid parameter group value for the real noise pixels; when it is determined that each pixel is marked, the centroid row and column coordinates of each spot are calculated according to the final centroid parameter group accumulated value of each spot. The invention also discloses a single-point noise-resistant light spot center positioning device. The method and device can remove noise points while extracting the light spot center, save data storage space, and realize real-time extraction of the light spot center.

Description

Spot center positioning method and device against single point noise

technical field

The invention relates to image processing technology, in particular to a spot center positioning method and device against single point noise.

Background technique

The spot image is common image information in existing image processing, and the center of the spot is an important feature of the spot image. Spot center is widely used in target tracking in machine vision, feature point extraction in pattern recognition, positioning of laser spot center in laser measurement and communication, and star point positioning of star sensors and sun sensors in attitude measurement components in aerospace applications Sun spot positioning, etc.

In practical applications, the captured spot images often contain noise points. These noise points are mainly caused by the pattern noise of the image sensor, usually appearing as discrete single-pixel points, and the gray value of the noise is large, which cannot be removed by thresholding. . The longer the exposure time of the image sensor, the more obvious it is. Therefore, in applications with a shorter exposure time, such as: when using a sun sensor, the noise points in the spot image are not obvious; however, in the application process of the star sensor In order to improve its sensitivity, the image sensor needs a longer exposure time, so the noise points in the spot image will be more obvious. In this case, the star sensor is required to have a certain anti-noise ability when performing positioning operations.

In the prior art, it is impossible to directly locate the spot center of the spot image containing noise points. One method is: first preprocess the image by filtering to remove the noise points, and then perform center positioning on the image spot. In this way, there is no doubt that It is necessary to increase the large data storage space to save the preprocessed image; moreover, because the spot image needs to be preprocessed in advance, the real-time extraction of the center of the spot cannot be realized, thereby affecting the processing speed of the spot image; The image is pre-processed, and the pre-processing operation usually needs to be implemented in a PC or an ARM processor, which cannot meet the requirements of device integration and miniaturization.

Another spot center positioning method is: first treat the noise point as a single pixel spot, and then remove the noise point according to the total number of pixels of the spot. The specific implementation process of this method can be found in the patent No. ZL200610161802.6 and patent The two patents No. 03105743.6 treat the noise as light spots first, so it is necessary to reserve the storage space required for the maximum light spot: there are 6 real light spots in the image, and 5 noise points, and the maximum light spot requires The parameter storage space is 12 bytes, then, the required storage space when processing this image is then (6+5)×12=132 bytes, so this method will require more images with single-point noise Great storage space.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a method and device for locating the spot center against single-point noise, which removes noise points in the spot image while extracting the center of the spot, saves data storage space, and realizes the location of the center of the spot at the same time. Extraction in real time.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

The invention provides a method for locating the spot center against single point noise, the method comprising:

Compare the gray value of each pixel of the spot image with the preset threshold in turn, mark the pixels whose gray value is less than the threshold as background pixels, and judge whether the adjacent pixels are background pixels for the pixels whose gray value is greater than the threshold Pixel, if yes, then mark the current pixel as a noise pixel; if not, then determine that the current pixel is a spot pixel, and mark the current spot pixel according to the marks of the adjacent pixels of the current pixel;

According to the marking of adjacent pixels, the centroid parameter group values are accumulated and stored for the spot pixels, and the centroid parameter group values are not accumulated and stored for the real noise pixels; after each pixel of the spot image has been marked, according to the final The accumulated value of the centroid parameter group is used to calculate the row and column coordinates of the centroid of each spot according to the first-order moment centroid calculation formula.

Wherein, the adjacent pixels of the current pixel include: a left pixel, an upper pixel, and an upper right pixel.

The marking of the current pixel according to the marking of the adjacent pixels of the current pixel is specifically:

Determine whether the pixel to the left of the current pixel is a noise pixel or a background pixel, if not, mark the current pixel as the value of the left pixel; otherwise,

Determine whether the upper pixel of the current pixel is a noise pixel or a background pixel, if not, mark the current pixel as the marked value of the upper pixel; otherwise,

Determine whether the upper pixel of the current pixel is a noise pixel, and at the same time determine whether the upper right pixel of the current pixel is not a noise pixel or a background pixel, if so, mark the current pixel as the marked value of the upper right pixel; otherwise, mark the current pixel New tag value for the spot.

According to the marks of adjacent pixels, the centroid parameter group values of the spot pixels are accumulated and stored, specifically including:

When it is judged that the grayscale of the current pixel is less than the threshold and the left pixel is not a background pixel or a noise pixel, it means that a row of effective pixels of the light spot is over, and the centroid parameter group value corresponding to the mark of the left pixel is accumulated and stored;

If the grayscale value of the current pixel is greater than the threshold, and the left pixel and the upper pixel of the current pixel are two effective spot pixels with different tag values, then the centroid parameter group value corresponding to the left pixel tag and the upper pixel tag corresponding The centroid parameter group values are accumulated, and the spot mark of the left pixel is updated to the spot mark of the upper pixel.

According to the marking of adjacent pixels, the centroid parameter group value is not accumulated and stored for the real noise pixel, specifically:

The gray value of the current pixel is less than the threshold value, and the left pixel of the current pixel is a noise pixel, then the left pixel is a real noise pixel, and the value of the centroid parameter set is not accumulated and stored.

The present invention also provides a light spot center positioning device that is resistant to single-point noise, and the device includes: a light spot pixel identification module, a centroid parameter group accumulation module, and a centroid coordinate calculation module; wherein,

The spot pixel identification module is configured to sequentially compare the gray value of each pixel of the externally input spot image with a preset threshold when triggered by the centroid parameter group accumulation module, and when it is determined to be less than the threshold, the pixel Mark it as a background pixel; when it is determined that it is greater than the threshold, judge whether the adjacent pixel of the pixel is a background pixel, if yes, then mark the pixel as a noise pixel; if not, then determine that the pixel is a spot pixel, according to the mark the pixel by marking the pixels adjacent to the pixel;

The centroid parameter group accumulation module is used for accumulating and storing the centroid parameter group value of the spot pixel according to the marking of adjacent pixels of the spot pixel marked by the spot pixel identification module, and not performing the centroid parameter set for the real noise pixel Accumulation and storage of values, and judging whether each pixel of the spot image has been marked to end, and when the end is determined, the centroid coordinate calculation module is triggered; when the centroid coordinate calculation module is triggered by the centroid parameter group accumulation module, according to the centroid The final centroid parameter group accumulation value of each spot obtained by the parameter group accumulation module is calculated according to the first-order moment centroid calculation formula to calculate the centroid row and column coordinates of each spot.

Wherein, the spot pixel identification module further includes: a threshold judgment processing module and an adjacent pixel judgment marking module; wherein,

The threshold judgment processing module is configured to sequentially compare the gray value of each pixel of the externally input spot image with a preset threshold when triggered by the centroid parameter group accumulation module, and when it is determined to be less than or greater than the threshold, trigger the corresponding Adjacent pixel judgment marking module;

The adjacent pixel judging and marking module is used to mark pixels smaller than the threshold as background pixels after being triggered by the threshold judging processing module, or judge whether the adjacent pixels of the pixel larger than the threshold are background pixels, and if so, set all The pixel is marked as a noise pixel; if not, it is determined that the pixel is a spot pixel, and the pixel is marked according to the marks of adjacent pixels of the pixel; correspondingly,

The centroid parameter group accumulating module is further used to accumulate and store the centroid parameter group value of the spot pixel according to the marking of adjacent pixels of the spot pixel marked by the adjacent pixel judging and marking module, and judge each spot image Whether all pixels have been marked to end, when it is determined to end, trigger the center of mass coordinate calculation module.

Wherein, the centroid parameter group accumulation module performs centroid parameter group value accumulation and storage on the spot pixels, specifically:

When it is determined that the gray value of the current pixel is less than the threshold, and the left pixel of the current pixel is not a background pixel or a noise pixel, the value of the centroid parameter group of the light spot corresponding to the left pixel mark is accumulated and stored;

When it is determined that the gray value of the current pixel is greater than the threshold, and the left pixel and the upper pixel of the current pixel are two effective spot pixels with different tag values, the centroid parameter group value corresponding to the left pixel tag is compared with the centroid corresponding to the upper pixel tag The value of the parameter group is accumulated, and the spot mark to which the left pixel belongs is updated to the spot mark to which the upper pixel belongs.

Wherein, the centroid parameter group accumulation module does not carry out the accumulation and storage of the centroid parameter group values for the real noise pixels, specifically:

When it is determined that the gray value of the current pixel is less than the threshold, and the left pixel of the current pixel is marked as a noise pixel, then the left pixel is a real noise pixel, and the value of the centroid parameter group is not accumulated and stored.

The spot center positioning method and device against single-point noise provided by the present invention sequentially compare the gray value of each pixel of the spot image with a preset threshold value, and mark the pixels whose gray value is smaller than the threshold value as background pixels. For a pixel whose gray value is greater than the threshold, judge whether its adjacent pixel is a background pixel. If yes, mark the current pixel as a noise pixel; if not, determine that the current pixel is a spot pixel. to mark the current spot pixel; according to the marking of adjacent pixels, the centroid parameter group value is accumulated and stored for the spot pixel, and the centroid parameter group value is not accumulated and stored for the real noise pixel; after confirming that each pixel of the spot image has been marked , calculate the row and column coordinates of the centroid of each spot according to the accumulated value of the final centroid parameter set of each spot. The invention can identify and remove noise points in the image during the extraction process of the spot center of the spot image, save data storage space, and realize real-time extraction of the spot center at the same time.

In addition, since the operation of extracting the spot center and the operation of removing noise points are processed in parallel in the present invention, the real-time extraction of the spot center can be realized, which ensures the processing speed of the spot image; meanwhile, the two parallel operations can be performed through a field programmable gate array (FPGA) or Application-specific integrated circuit (ASIC) to achieve, effectively use the parallel processing capability of FPGA or ASIC, can avoid the preprocessing operation that needs to be realized in PC or ARM processor in the prior art, that is to say, only need pass FPGA or ASIC The positioning of the center of the light spot and the removal of noise points can be realized, so the requirements of integration and miniaturization of devices can be met.

Description of drawings

Fig. 1 is the implementation flow schematic diagram of the spot center localization method of anti-single-point noise of the present invention;

Fig. 2 is a schematic diagram of the implementation process of the method for marking the current pixel according to the marking of the adjacent pixels of the current pixel according to the present invention;

FIG. 3 is a schematic diagram of an image during spot pixel marking in an embodiment of the present invention;

Fig. 4 is a schematic diagram of an image after all the pixels of the light spot in the light spot are marked in the embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a spot center positioning device for resisting single-point noise in the present invention.

Detailed ways

The basic idea of the present invention is: sequentially compare the gray value of each pixel of the spot image with the preset threshold, mark the pixels whose gray value is smaller than the threshold as background pixels, and judge the pixels whose gray value is larger than the threshold Whether its adjacent pixel is a background pixel, if yes, mark the current pixel as a noise pixel; if not, determine that the current pixel is a spot pixel, and mark the current spot pixel according to the marks of the adjacent pixels of the current pixel;

According to the marking of adjacent pixels, the centroid parameter group values are accumulated and stored for the spot pixels, and the centroid parameter group values are not accumulated and stored for the real noise pixels; after each pixel of the spot image has been marked, according to the final The centroid row and column coordinates of each light spot are calculated from the accumulated value of the centroid parameter group, so that the center of the light spot can be determined.

Here, when calculating the row and column coordinates of the centroid of the spot, the first-order moment centroid calculation formula is used, as follows:

$\mathrm{<span\; class="notranslate">\; Xc</span>}<span\; class="notranslate">\; =</span>\frac{\underset{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; x</span>}}{\underset{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ $\mathrm{<span\; class="notranslate">\; Yc</span>}<span\; class="notranslate">\; =</span>\frac{\underset{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}}{\underset{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\underset{\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span>}$

Wherein, the centroid parameter group value refers to the value of the numerator and the denominator in the formula, that is, the cumulative value of the product of the gray value and the coordinate value and the cumulative value of the gray value; the I (x, y) represents the gray value of the pixel The x and y are the row and column coordinates corresponding to the pixel, and the Xc and Yc are the row and column coordinates of the spot centroid respectively.

In order to identify the image spot from the background of the spot image, the present invention adopts the method of separately marking the background pixel, the noise pixel and the spot pixel. For this reason, the adjacent pixels of the current pixel are set as: left pixel, upper pixel, For the upper right pixel, background pixels, noise pixels and speckle pixels can be distinguished according to the marker value.

Here, when the accumulation operation is performed on the value of the spot centroid parameter group to which the current pixel belongs, the pixels judged to be noise are not accumulated, so as to achieve the purpose of real-time noise removal.

In the present invention, the spot image is marked from top to bottom and from left to right, that is, starting from the first pixel on the upper left, and finally marking the last pixel on the lower right. Of course, other orders can also be used Mark the pixels of the spot image.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of the implementation process of the spot center positioning method against single point noise of the present invention, as shown in Figure 1, the implementation process of the method is as follows:

Step 101: Initialize adjacent pixel marks and spot marks, and then read the first pixel of the spot image;

Specifically: mark the upper pixel, the left pixel and the upper right pixel as background pixels, and at the same time initialize the new mark of the light spot to the initial value of the light spot mark, and then read the first pixel of the light spot image.

In the present invention, the initial values of the flags of the background pixels, noise pixels, and spot pixels can be arbitrary values that are not equal to each other, and the purpose of the flags is to distinguish different types of pixels. For example: the flag of the background pixel can be set to 0, the flag of the noise pixel can be set to 1, and the initial value of the spot flag can be set to 2. The spot is composed of multiple spot pixels, and all spot pixels in the same spot finally correspond to the same The tag value of the facula to which it belongs.

Step 102: judging whether the gray value of the current pixel is greater than the preset threshold, if greater, then perform step 103; if less, then perform step 106;

Here, the preset threshold can be set according to different image sensors, and the corresponding thresholds of different image sensors are slightly different; for pixels with a grayscale value greater than the preset threshold, they may be noise points or spot pixels. Perform follow-up operations for further judgment.

Step 103: determine whether the adjacent pixel of the current pixel is a background pixel, if yes, mark the current pixel as a noise pixel, and then perform step 108; if not, then determine that the current pixel is a spot pixel, and then perform step 104;

Specifically: determine whether the left pixel and the upper pixel of the current pixel are background pixels, for example: determine whether the marks of the left pixel and the upper pixel are 0, if so, mark the current pixel as a noise pixel, for example: set the current pixel If it is marked as 1, then step 108 is performed; if not, it can be determined that the current pixel belongs to an effective spot pixel, and then step 104 is performed.

Step 104: mark the current spot pixel according to the marks of the adjacent pixels of the current pixel;

Specifically: mark the current pixel according to the marks of the upper pixel, left pixel and upper right pixel of the current spot pixel, as shown in Figure 2, this step specifically includes the following process:

Step 104A: judge whether the left pixel of the current pixel is a noise pixel or a background pixel according to the marked value, if not, mark the current pixel as the marked value of the left pixel; otherwise, perform step 104B;

Specifically: judge whether the left pixel of the current pixel is a noise pixel or a background pixel by the mark value of the left pixel, for example: judge whether the mark value of the left pixel of the current pixel is greater than 1, if it is greater than 1, it means that the left pixel is If it is not a noise pixel or a background pixel, that is, the left pixel is a spot pixel, then mark the current pixel as the mark value of the left pixel; otherwise, if the mark value of the left pixel of the current pixel is less than or equal to 1, then perform step 104B .

Step 104B: judge whether the upper pixel of the current pixel is a noise pixel or a background pixel according to the marked value, if not, mark the current pixel as the marked value of the upper pixel; otherwise, execute step 104C;

Specifically: judge whether the pixel above the current pixel is a noise pixel or a background pixel by the mark value of the above pixel, for example: judge whether the mark value of the pixel above the current pixel is greater than 1, if it is greater than 1, it means that the above pixel is a spot pixel, then Mark the current pixel as the marked value of the pixel above; otherwise, if the marked value of the pixel above the current pixel is less than or equal to 1, then perform step 104C.

Step 104C: judging whether the upper pixel of the current pixel is a noise pixel according to the flag value, and simultaneously judging whether the upper right pixel of the current pixel is not a noise pixel or a background pixel, if so, marking the current pixel as the flag value of the upper right pixel; Otherwise, mark the current pixel as the flare new mark value.

Specifically: judge whether the upper pixel of the current pixel is a noise pixel through the flag value, and whether the upper right pixel of the current pixel is not a noise pixel or a background pixel, for example: judge whether the flag value of the upper pixel of the current pixel is equal to 1, and the current Whether the mark value of the upper right pixel of the pixel is greater than 1, if yes, mark the current pixel as the mark value of the upper right pixel; otherwise, mark the current pixel as another new spot mark, that is, the current spot pixel may belong to another Different light spots may also be the same light spot. If they are the same light spot, the centroid parameter values of the same light spot with different marks can be merged and accumulated through subsequent steps 105 and 107 .

Step 105: Determine whether the left pixel and the upper pixel of the current pixel are spot pixels, and whether the flag values of the two are the same, if they are the same, perform step 108; otherwise, perform step 107.

Step 107: Accumulate the centroid parameter set value corresponding to the left pixel mark and the centroid parameter set value corresponding to the upper pixel mark, and update the spot mark to which the left pixel belongs to the light spot mark to which the upper pixel belongs;

For example: take the spot pixel in the lower left spot shown in Figure 3 as an example, if the mark value of the upper pixel of the current spot pixel is 4, and the mark value of the left pixel is 5, then the centroid parameter group corresponding to mark 5 is accumulated The value is added to the cumulative value of the centroid parameter group corresponding to mark 4, and the result is updated to the new cumulative value of the centroid parameter group corresponding to the corresponding spot 4, and the corresponding spot mark corresponding to mark 5 is also updated to 4, and finally all the spot pixels included in the same spot are the same, as shown in Figure 4.

Here, what needs to be explained with respect to FIG. 3 is that the pixels marked 1 in the light spot in the figure are effective light spot pixels, and the discrete pixels marked 1 in the figure are effective noise pixels.

Step 106: mark the current pixel as a background pixel, update the value of the spot mark, and judge whether the left pixel of the current pixel is a spot pixel, and if so, accumulate and store the value of the centroid parameter group of the light spot corresponding to the left pixel mark, Execute step 108 afterwards; Otherwise, do not carry out centroid parameter group value accumulation and storage, directly execute step 108;

Specifically: mark the current pixel as a background pixel, for example: set the mark value of the current pixel to 0, and update the spot mark value to be not equal to the noise pixel mark or the background pixel mark, and not equal to any one of the current light spot mark value Value, used to mark the next spot. At the same time, judge whether the left pixel of the current pixel is a spot pixel, for example: judge whether the mark value of the left pixel of the current pixel is greater than 1, if it is greater than 1, it indicates that the left pixel is a spot pixel, then accumulate and store the left The pixel mark corresponds to the value of the centroid parameter group of the facula, and then perform step 108; otherwise, if the mark value of the left pixel is equal to 1 or less than 1, the left pixel is a real noise pixel or background, and the centroid parameter group value is not accumulated and stored , directly execute step 108.

In the present invention, the rule for accumulative storage of the effective spot centroid parameter group is: when a row of effective pixels of the spot ends, the value of the corresponding spot centroid parameter group corresponding to the row is accumulated and stored, and when the same spot has different marks, the The centroid parameter group values of different markers are merged and accumulated, and the corresponding facula markers of different markers are updated to the same facula marker.

Step 108: judge whether the current pixel is the last one of a row of pixels, if so, initialize the left pixel mark as a background pixel, and execute step 110; otherwise, execute step 109;

Specifically: judge whether the current pixel is the last one of a row of pixels, for example: if the spot image is an image of 1024x1024 pixels, it can be judged whether the current pixel is the 1024th pixel of a row of pixels, if so, initialize the left pixel is the background pixel for judging the first pixel in the next row, and execute step 110; otherwise, execute step 109.

Step 109: update the adjacent pixel mark of the current pixel, and store the mark value of the current pixel at the same time, then read the next pixel of the row, and execute step 102;

Specifically: update the left pixel mark of the current pixel to the current pixel mark, update the upper pixel mark of the current pixel to the upper right pixel mark, and update the upper right pixel mark of the current pixel to the right side adjacent to the current upper right pixel The mark of the pixel is ready to read the next pixel of the row, and store the mark value of the current pixel, then read the next pixel of the row, and return to step 102.

Step 110: judge whether the current row is the last row of the spot image, if not, execute step 111; if yes, execute step 112;

Specifically: judge whether the current row is the last row of the spot image, for example: if the spot image is an image of 1024×1024 pixels, then it can be judged whether the current row is the 1024th pixel of a certain column of pixels, if not, then execute step 111; if If yes, go to step 112.

Step 111: update the adjacent pixel mark of the current pixel, then read the first pixel in the next row, and execute step 102;

Specifically: update the upper pixel mark and the upper right pixel mark of the current pixel, the update method is the same as that described in step 108, and then read the first pixel in the next row, and execute step 102.

Step 112: Calculate the centroid row and column coordinates of each spot according to the accumulated value of the final centroid parameter group of each spot;

Specifically, according to the accumulated value of the final centroid parameter group of each spot, the row and column coordinates of the centroid of each spot are calculated according to the first-order moment centroid calculation formula, that is, the positioning of the center of the spot is realized. The calculation method of this step is a prior art, which is not described here. More details.

In order to realize the above method, the present invention also provides a spot center positioning device against single point noise, as shown in Figure 4, the device includes: spot pixel identification module, centroid parameter group accumulation module and centroid coordinate calculation module; wherein,

The spot pixel identification module is configured to sequentially compare the gray value of each pixel of the externally input spot image with a preset threshold when triggered by the centroid parameter group accumulation module, and when it is determined to be less than the threshold, the pixel Mark it as a background pixel; when it is determined that it is greater than the threshold, judge whether the adjacent pixel of the pixel is a background pixel, if yes, then mark the pixel as a noise pixel; if not, then determine that the pixel is a spot pixel, according to the mark the pixel by marking the pixels adjacent to the pixel;

The centroid parameter group accumulation module is used for accumulating and storing the centroid parameter group value of the spot pixel according to the marking of adjacent pixels of the spot pixel marked by the spot pixel identification module, and not performing the centroid parameter set for the real noise pixel Accumulate and store the values, and judge whether each pixel of the spot image has been marked to end, and when the end is determined, trigger the centroid coordinate calculation module;

The centroid coordinate calculation module is configured to calculate the centroid row and column coordinates of each spot according to the final centroid parameter set accumulation value of each spot obtained by the centroid parameter set accumulation module when triggered by the centroid parameter set accumulation module.

The spot pixel identification module further includes: a threshold judgment processing module and an adjacent pixel judgment marking module; wherein,

The threshold judgment processing module is configured to sequentially compare the gray value of each pixel of the externally input spot image with a preset threshold when triggered by the centroid parameter group accumulation module, and when it is determined to be less than or greater than the threshold, trigger the corresponding Adjacent pixel judgment marking module;

The adjacent pixel judging and marking module is used to mark pixels smaller than the threshold as background pixels after being triggered by the threshold judging processing module, or judge whether the adjacent pixels of the pixel larger than the threshold are background pixels, and if so, set all The pixel is marked as a noise pixel; if not, it is determined that the pixel is a spot pixel, and the pixel is marked according to the marks of adjacent pixels of the pixel; correspondingly,

The centroid parameter group accumulating module is further used to accumulate and store the centroid parameter group value of the spot pixel according to the marking of adjacent pixels of the spot pixel marked by the adjacent pixel judging and marking module, and judge each spot image Whether all pixels have been marked to end, when it is determined to end, trigger the center of mass coordinate calculation module.

The centroid parameter group accumulation module performs centroid parameter group value accumulation and storage on the spot pixels, specifically:

When it is determined that the gray value of the current pixel is less than the threshold, and the left pixel of the current pixel is not a background pixel or a noise pixel, the value of the centroid parameter group of the light spot corresponding to the left pixel mark is accumulated and stored;

When it is determined that the gray value of the current pixel is greater than the threshold, and the left pixel and the upper pixel of the current pixel are two effective spot pixels with different tag values, the centroid parameter group value corresponding to the left pixel tag is compared with the centroid corresponding to the upper pixel tag The value of the parameter group is accumulated, and the spot mark to which the left pixel belongs is updated to the spot mark to which the upper pixel belongs.

The centroid parameter group accumulation module does not carry out the accumulation and storage of the centroid parameter group value to the real noise pixel, specifically:

When it is determined that the gray value of the current pixel is less than the threshold, and the left pixel of the current pixel is marked as a noise pixel, then the left pixel is a real noise pixel, and the value of the centroid parameter group is not accumulated and stored.

In the actual application process, FPGA or ASIC can be adopted to realize the device of the present invention, specifically as follows:

The threshold comparator, left flag register, upper flag register, right upper flag register, new flag register, current flag register, spot flag judger, noise flag judger, row comparator, column comparator and Spot index register; where,

The threshold comparator is used to judge whether the gray value of the current pixel is greater than a preset threshold;

The left flag register, the upper flag register, the upper right flag register, the new flag register and the current flag register are respectively used to store and output the corresponding left pixel, upper pixel, upper right pixel, new flag value and flag of the current pixel value;

The spot mark determiner and the noise mark determiner are used to determine which effective spot pixel the current pixel whose gray value is greater than the threshold belongs to, or the current pixel may be a noise point pixel;

The row comparator is used to judge whether the current row of pixels is the last row of the current image;

The column comparator is used to determine whether the current pixel is the last pixel of a row of pixels;

The light spot index register is used to store the mark of the light spot corresponding to the pixel mark, so as to establish the index of the pixel mark and the light spot mark, so as to ensure the correct accumulation of the centroid parameter group values of each light spot.

In addition, a row multiplier, a column multiplier, a row adder, a column adder, a grayscale adder, a row parameter memory, a column parameter memory, and a grayscale parameter memory can be set in the centroid parameter group accumulation module; wherein,

The row multiplier and the column multiplier are respectively used to calculate the product of the pixel gray value and the row coordinate, and the product of the pixel gray value and the column coordinate;

The row adder, column adder, and grayscale adder are respectively used to accumulate the product of the current pixel grayscale value and the row coordinate, the product of the grayscale value and the column coordinate, and the current pixel grayscale value and the current location of the current pixel grayscale value and its associated light spot. The corresponding parameter group value;

The shown row parameter memory, column parameter memory and gray scale parameter memory are respectively used to store the centroid parameter group value of each corresponding light spot.

In addition, a row coordinate divider and a column coordinate divider may be set in the centroid coordinate calculation module to calculate the row coordinate and column coordinate of each light spot corresponding to the centroid.

Certainly, in the actual application process, the internal structures of the spot pixel identification module, the centroid parameter group accumulation module and the centroid coordinate calculation module can also adopt other combinations.

The above description is only a preferred embodiment of the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the within the protection scope of the present invention.

Claims (9)

1. A spot center positioning method for resisting single-point noise is characterized by comprising the following steps:

comparing the gray value of each pixel of the light spot image with a preset threshold value in sequence, marking the pixel with the gray value smaller than the threshold value as a background pixel, judging whether the adjacent pixel is the background pixel or not for the pixel with the gray value larger than the threshold value, and if so, marking the current pixel as a noise pixel; if not, determining that the current pixel is the light spot pixel, and marking the current light spot pixel according to the marks of the adjacent pixels of the current pixel;

according to the marks of the adjacent pixels, the centroid parameter set value accumulation and storage are carried out on the light spot pixels, and the centroid parameter set value accumulation and storage are not carried out on the real noise pixels; and after the fact that each pixel of the light spot image is marked is determined, calculating the mass center row-column coordinate of each light spot according to a first moment mass center calculation formula and the final mass center parameter set accumulated value of each light spot.

2. The single-point noise resistant spot center positioning method according to claim 1, wherein the neighboring pixels of the current pixel comprise: left pixel, upper pixel, and upper right pixel.

3. The method for positioning a center of a light spot for resisting single-point noise according to claim 2, wherein the current pixel is marked according to marks of neighboring pixels of the current pixel, specifically:

judging whether the left pixel of the current pixel is a noise pixel or a background pixel, if not, marking the current pixel as a marking value of the left pixel; if not, then,

judging whether the pixel above the current pixel is a noise pixel or a background pixel, if not, marking the current pixel as a marking value of the pixel above; if not, then,

judging whether the pixel above the current pixel is a noise pixel or not, judging whether the pixel above the right of the current pixel is not a noise pixel or a background pixel or not, and if so, marking the current pixel as a marking value of the pixel above the right; otherwise, marking the current pixel as a new light spot marking value.

4. The method for positioning a spot center resistant to single-point noise according to claim 2 or 3, wherein the accumulating and storing the centroid parameter set values of the spot pixels according to the marks of the adjacent pixels specifically comprises:

if the gray value of the current pixel is smaller than the threshold value and the left pixel of the current pixel is not the background pixel or the noise pixel, accumulating and storing the corresponding spot centroid parameter group value of the left pixel mark;

and if the gray value of the current pixel is greater than the threshold value and the left pixel and the upper pixel of the current pixel are effective light spot pixels with different mark values, accumulating the centroid parameter group value corresponding to the left pixel mark and the centroid parameter group value corresponding to the upper pixel mark, and updating the light spot mark to which the left pixel belongs to the light spot mark to which the upper pixel belongs.

5. The method for positioning the center of a spot of single-point noise resistant according to claim 2 or 3, wherein the centroid parameter set value accumulation and storage are not performed on the true noise pixel according to the marks of the adjacent pixels, specifically:

and if the gray value of the current pixel is smaller than the threshold value and the left pixel of the current pixel is a noise pixel, the left pixel is a real noise pixel, and the accumulation storage of the centroid parameter set value is not performed.

6. A single point noise resistant spot centering device, comprising: the device comprises a light spot pixel identification module, a centroid parameter set accumulation module and a centroid coordinate calculation module; wherein,

the light spot pixel identification module is used for sequentially comparing the gray value of each pixel of the externally input light spot image with a preset threshold value when being triggered by the centroid parameter group accumulation module, and marking the pixel as a background pixel when the gray value is smaller than the threshold value; when the pixel is determined to be larger than the threshold value, judging whether the adjacent pixel of the pixel is a background pixel, and if so, marking the pixel as a noise pixel; if not, determining that the pixel is a light spot pixel, and marking the pixel according to the marks of the adjacent pixels of the pixel;

the centroid parameter group accumulation module is used for accumulating and storing the centroid parameter group values of the light spot pixels according to the marks of the adjacent pixels of the light spot pixels marked by the light spot pixel identification module, and does not accumulate and store the centroid parameter group values of the real noise pixels, judging whether each pixel of the light spot image is marked to be ended or not, and triggering the centroid coordinate calculation module when the end is determined;

and the centroid coordinate calculation module is used for calculating the centroid row-column coordinates of each light spot according to a first-order moment centroid calculation formula according to the final centroid parameter set accumulated value of each light spot obtained by the centroid parameter set accumulation module when the centroid coordinate calculation module is triggered by the centroid parameter set accumulation module.

7. The single-point noise resistant spot center positioning device according to claim 6, wherein the spot pixel identification module further comprises: the device comprises a threshold judgment processing module and an adjacent pixel judgment marking module; wherein,

the threshold judgment processing module is used for comparing the gray value of each pixel of the externally input light spot image with a preset threshold value in sequence when the centroid parameter set accumulation module is triggered, and triggering the adjacent pixel judgment marking module when the gray value is smaller than or larger than the threshold value;

the adjacent pixel judgment marking module is used for marking the pixel smaller than the threshold value as a background pixel or judging whether the adjacent pixel of the pixel larger than the threshold value is the background pixel or not after being triggered by the threshold value judgment processing module, and if so, marking the pixel as a noise pixel; if not, determining that the pixel is a light spot pixel, and marking the pixel according to the marks of the adjacent pixels of the pixel; accordingly, the method can be used for solving the problems that,

the centroid parameter group accumulation module is further used for performing centroid parameter group value accumulation and storage on the light spot pixel according to the mark of the adjacent pixel of the light spot pixel marked by the adjacent pixel judgment marking module.

8. The single-point noise resistant spot center positioning device according to claim 6 or 7, wherein the centroid parameter set accumulation module accumulates and stores the centroid parameter set values of the spot pixels, specifically:

when the gray value of the current pixel is smaller than the threshold value and the left pixel of the current pixel is not the background pixel or the noise pixel, accumulating and storing the corresponding spot centroid parameter group value of the left pixel mark;

and when the gray value of the current pixel is determined to be larger than the threshold value, and the left pixel and the upper pixel of the current pixel are effective light spot pixels with different mark values, accumulating the centroid parameter group value corresponding to the left pixel mark and the centroid parameter group value corresponding to the upper pixel mark, and updating the light spot mark to which the left pixel belongs to the light spot mark to which the upper pixel belongs.

9. The single-point noise resistant spot center positioning device according to claim 6 or 7, wherein the centroid parameter set accumulation module does not accumulate and store the centroid parameter set value for the true noise pixel, specifically:

and when the gray value of the current pixel is smaller than the threshold value and the left pixel of the current pixel is marked as the noise pixel, the left pixel is the real noise pixel, and the accumulation storage of the centroid parameter group value is not carried out.

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