Image binarization threshold (kirsch operator)

Image binarization threshold kirsch operator

The implementation of the kirsch operator is a little complicated. It uses eight templates to perform convolution and derivative for each pixel in the image. These eight templates represent eight directions, the maximum response is made to eight specific edge directions on the image. In the calculation, the maximum value is taken as the edge output of the image (the eight templates used in the preceding algorithm are provided in the implementation code below ). To help readers understand the implementation of the algorithm, we provide the function code to implement the algorithm. You can apply the Code to your project with slight changes.

Bool Kirsch (byte * pdata, int width, int height) {// Defines eight templates that implement the Kirsch algorithm; Int I, j, S, T, K, Max, sum [8]; Static A [3] [3] = {+ 5, + 5, + 5}, {-3,-3}, {-3,-3, -3 }}; Static A1 [3] [3] = {-3, + 5, + 5}, {-3, 0, + 5}, {-3,-3, -3 }}; Static A2 [3] [3] = {-3,-3, + 5}, {-3, 0, + 5}, {-3,-3, + 5 }}; Static A3 [3] [3] = {-3,-3,-3}, {-3, 0, + 5}, {-3, + 5, + 5 }}; Static A4 [3] [3] = {-3,-3,-3}, {-3,-3}, {+ 5, + 5, + 5 }}; Static A5 [3] [3] = {-3,-3,-3}, {+ 5, 0,-3}, {+ 5, + 5, -3 }}; Static A6 [3] [3] = {+ 5,-3,-3}, {+ 5,-3}, {+ 5,-3, -3 }}; Static A7 [3] [3] = {+ 5, + 5,-3}, {+ 5,-3}, {-3,-3, -3 }}; Byte * pdata1; If (pdata = NULL) { Afxmessagebox ("image data is empty. Please read image data! "); Return false; } Pdata1 = (byte *) New char [width * Height]; If (pdata1 = NULL) { Afxmessagebox ("Image Buffer data zone application failed. Please apply for image data buffer again! "); Return false; } Memcpy (pdata1, pdata, width * 8 * Height ); // The kirsch operator is used to calculate the derivative of each pixel in eight directions ;; For (I = 1; I For (j = 1; j <width-1; j ++) { Sum [1] = sum [2] = sum [3] = sum [4] = sum [5] = sum [6] = sum [7] = sum [8] = 0; For (t =-1; t <2; t ++) { For (S =-1; S <2; s ++) {Sum [1] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A [1 + T] [1 + S]; Sum [2] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A1 [1 + T] [1 + S]; sum [3] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A2 [1 + T] [1 + S]; sum [4] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A3 [1 + T] [1 + S]; sum [5] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A4 [1 + T] [1 + S]; sum [6] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A5 [1 + T] [1 + S]; sum [7] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A6 [1 + T] [1 + S]; sum [8] + = * (pdata + widthbytes (width * 8) * (I + t) + J + S) * A7 [1 + T] [1 + S]; } } // Obtain the derivative of the maximum direction; For (k = 0; k <8; k ++) { Max = 0; If (max <sum [k]) Max = sum [k]; } If (max <0) Max = 0; If (max> 255) Max = 255; * (Pdata1 + width * 8 * I + J) = max; } Memcpy (pdata, pdata1, width * 8 * Height ); Delete pdata1; Return true; }