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Update thinning.cpp
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‎modules/ximgproc/src/thinning.cpp‎

Lines changed: 144 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -9,6 +9,9 @@ namespace ximgproc {
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int guo_hall_thinning(uint8_t* binary_image, size_t width, size_t height);
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int zhang_suen_thinning(uint8_t* binary_image, size_t width, size_t height);
12+
void bitwiseANDInPlace(uint8_t* a, const uint8_t* b, size_t size);
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void thinninggh(InputArray input, OutputArray output, int thinningType);
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/**
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* Perform a logical AND on a memory array (a), ANDing it with another array (b).
@@ -147,6 +150,8 @@ int zhang_suen_thinning(uint8_t* binary_image, size_t width, size_t height) {
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// Apply the thinning procedure to a given image
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void thinning(InputArray input, OutputArray output, int thinningType){
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if(thinningType == THINNING_GUOHALL)
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return thinninggh(input, output, thinningType);
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Mat processed = input.getMat().clone();
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CV_CheckTypeEQ(processed.type(), CV_8UC1, "");
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@@ -155,8 +160,145 @@ void thinning(InputArray input, OutputArray output, int thinningType){
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if(thinningType == THINNING_ZHANGSUEN)
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zhang_suen_thinning(processed.data, processed.cols, processed.rows);
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158-
if(thinningType == THINNING_GUOHALL)
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guo_hall_thinning(processed.data, processed.cols, processed.rows);
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processed *= 255;
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output.assign(processed);
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}
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// look up table - there is one entry for each of the 2^8=256 possible
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// combinations of 8 binary neighbors.
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static uint8_t lut_zhang_iter0[] = {
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1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1,
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0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1,
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0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1,
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0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1,
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1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1,
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1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0,
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1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
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1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1};
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static uint8_t lut_zhang_iter1[] = {
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1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1,
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0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1,
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0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1,
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0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1,
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0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0,
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1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1,
209+
0, 1, 1, 1};
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static uint8_t lut_guo_iter0[] = {
212+
1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1,
213+
0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
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0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1,
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0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1,
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0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1,
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0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0,
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1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1};
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232+
static uint8_t lut_guo_iter1[] = {
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1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
241+
0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1,
243+
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0,
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1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1,
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1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
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1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1,
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1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1,
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1, 1, 1, 1};
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253+
// Applies a thinning iteration to a binary image
254+
static void thinningIteration(Mat &img, Mat &marker, const uint8_t* const lut) {
255+
int rows = img.rows;
256+
int cols = img.cols;
257+
marker.col(0).setTo(1);
258+
marker.col(cols - 1).setTo(1);
259+
marker.row(0).setTo(1);
260+
marker.row(rows - 1).setTo(1);
261+
262+
marker.forEach<uchar>([=](uchar& value, const int postion[]) {
263+
int i = postion[0];
264+
int j = postion[1];
265+
if (i == 0 || j == 0 || i == rows - 1 || j == cols - 1) { return; }
266+
267+
auto ptr = img.ptr(i, j); // p1
268+
uchar p2 = ptr[-cols];
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uchar p3 = ptr[-cols + 1];
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uchar p4 = ptr[1];
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uchar p5 = ptr[cols + 1];
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uchar p6 = ptr[cols];
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uchar p7 = ptr[cols - 1];
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uchar p8 = ptr[-1];
275+
uchar p9 = ptr[-cols - 1];
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277+
int neighbors = p9 | (p2 << 1) | (p3 << 2) | (p4 << 3) | (p5 << 4) | (p6 << 5) | (p7 << 6) | (p8 << 7);
278+
value = lut[neighbors];
279+
});
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281+
img &= marker;
282+
marker.setTo(0);
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}
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// Apply the thinning procedure to a given image
286+
void thinninggh(InputArray input, OutputArray output, int thinningType){
287+
Mat processed = input.getMat().clone();
288+
CV_CheckTypeEQ(processed.type(), CV_8UC1, "");
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// Enforce the range of the input image to be in between 0 - 255
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processed /= 255;
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Mat prev = processed.clone();
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Mat marker = Mat::zeros(processed.size(), CV_8UC1);
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const auto lutIter0 = (thinningType == THINNING_GUOHALL) ? lut_guo_iter0 : lut_zhang_iter0;
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const auto lutIter1 = (thinningType == THINNING_GUOHALL) ? lut_guo_iter1 : lut_zhang_iter1;
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do {
296+
thinningIteration(processed, marker, lutIter0);
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thinningIteration(processed, marker, lutIter1);
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const auto res = cv::norm(processed, prev, cv::NORM_L1);
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if (res <= 0) { break; }
300+
processed.copyTo(prev);
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} while (true);
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161303
processed *= 255;
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output.assign(processed);

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