0.20200319: add blur args

README.md

@@ -14,6 +14,10 @@ Build:
 
 Usage:
 
+  ./aithreshold in.png out.png [T=0.15] [part=8] [blur=0]
+
+Example:
+
   ./aithreshold images/image.png images/output.png
 
 image.png

man/man1/aithreshold.1

@@ -0,0 +1,26 @@
+.TH "AIThreshold" 1 "19 Mar 2020" 0.20200319 " User Manual"
+
+.SH NAME
+aithreshold
+
+.SH SYNOPSIS
+aithreshold <image_in> <image_out> [T=0.15] [part=8] [blur=0]
+
+.SH DESCRIPTION
+Adaptive Thresholding Using the Integral Image
+
+.SH EXAMPLE
+aithreshold image.png output.png 0.1 16 1
+
+.SH COPYRIGHT
+Copyright 2017-2020 zvezdochiot.
+ All rights reserved.
+
+.SH SEE ALSO
+ convert(1),
+ imgtxtenh(1),
+ imthreshold(1)
+
+.SH CONTACTS
+ Homepage: https://github.com/zvezdochiot/aithreshold
+ Email: zvezdochiot@users.sourceforge.net

src/aithreshold.cpp

@@ -5,9 +5,14 @@
 
 using namespace std;
 
-
 void thresholdIntegral(cv::Mat &inputMat, cv::Mat &outputMat, float T, int part)
 {
+    int nRows, nCols, S, s2, i, j;
+    int x1, y1, x2, y2, count, sum, ip, it;
+    cv::Mat sumMat;
+    int *p_y1, *p_y2;
+    uchar *p_inputMat, *p_outputMat;
+
     // accept only char type matrices
     CV_Assert(!inputMat.empty());
     CV_Assert(inputMat.depth() == CV_8U);
@@ -17,91 +22,64 @@ void thresholdIntegral(cv::Mat &inputMat, cv::Mat &outputMat, float T, int part)
     CV_Assert(outputMat.channels() == 1);
 
     // rows -> height -> y
-    int nRows = inputMat.rows;
+    nRows = inputMat.rows;
     // cols -> width -> x
-    int nCols = inputMat.cols;
+    nCols = inputMat.cols;
 
     // create the integral image
-    cv::Mat sumMat;
     cv::integral(inputMat, sumMat);
 
     CV_Assert(sumMat.depth() == CV_32S);
     CV_Assert(sizeof(int) == 4);
 
-    int S = MAX(nRows, nCols) / part;
+    S = MAX(nRows, nCols);
+    S = (S > (part + part)) ? (S / part) : 2;
 
     // perform thresholding
-    int s2 = S/2;
-    int x1, y1, x2, y2, count, sum;
-
-    // CV_Assert(sizeof(int) == 4);
-    int *p_y1, *p_y2;
-    uchar *p_inputMat, *p_outputMat;
+    s2 = S/2;
 
-    for( int i = 0; i < nRows; ++i)
+    for(i = 0; i < nRows; ++i)
     {
-        y1 = i-s2;
-        y2 = i+s2;
-
-        if (y1 < 0){
-            y1 = 0;
-        }
-        if (y2 >= nRows) {
-            y2 = nRows-1;
-        }
+        y1 = (i < s2) ? 0 : (i - s2);
+        y2 = ((i + s2) < nRows) ? (i + s2) : (nRows - 1);
 
         p_y1 = sumMat.ptr<int>(y1);
         p_y2 = sumMat.ptr<int>(y2);
         p_inputMat = inputMat.ptr<uchar>(i);
         p_outputMat = outputMat.ptr<uchar>(i);
 
-        for ( int j = 0; j < nCols; ++j)
+        for (j = 0; j < nCols; ++j)
         {
-            // set the SxS region
-            x1 = j-s2;
-            x2 = j+s2;
+            x1 = (j < s2) ? 0 : (j - s2);
+            x2 = ((j + s2) < nCols) ? (j + s2) : (nCols - 1);
 
-            if (x1 < 0) {
-                x1 = 0;
-            }
-            if (x2 >= nCols) {
-                x2 = nCols-1;
-            }
-
-            count = (x2-x1)*(y2-y1);
+            count = (x2 - x1) * (y2 - y1);
 
             // I(x,y)=s(x2,y2)-s(x1,y2)-s(x2,y1)+s(x1,x1)
             sum = p_y2[x2] - p_y1[x2] - p_y2[x1] + p_y1[x1];
 
-            if ((int)(p_inputMat[j] * count) < (int)(sum * (1.0f - T)))
-                p_outputMat[j] = 0;
-            else
-                p_outputMat[j] = 255;
+            ip = (int)(p_inputMat[j] * count);
+            it = (int)(sum * (1.0f - T));
+            p_outputMat[j] = (ip < it) ? 0 : 255;
         }
     }
 }
 
-
 int main(int argc, char *argv[])
 {
     float T = 0.15f;
-    int part = 8;
+    int part = 8, blur = 0;
     printf("Adaptive Integral Threshold.\n");
     if (argc < 3)
     {
-        printf("Usage: aithreshold image_in image_out [T=0.15] [part=8]\n");
+        printf("Usage: aithreshold image_in image_out [T=0.15] [part=8] [blur=0]\n");
         return 0;
     }
     // Load the image
     cv::Mat src = cv::imread(argv[1]);
-    if (argc > 3)
-    {
-        T = atof(argv[3]);
-    }
-    if (argc > 4)
-    {
-        part = atoi(argv[4]);
-    }
+    if (argc > 3) T = atof(argv[3]);
+    if (argc > 4) part = atoi(argv[4]);
+    if (argc > 5) blur = atoi(argv[5]);
 
     // Check if image is loaded fine
     if(src.empty()) {
@@ -121,11 +99,14 @@ int main(int argc, char *argv[])
         gray = src;
     }
 
+    printf("T: %f, part: %d, blur: %d\n", T, part, blur);
+    blur++;
+    if (blur > 1) cv::blur(gray, gray, cv::Size(blur, blur));
     cv::Mat bw2 = cv::Mat::zeros(gray.size(), CV_8UC1);
     thresholdIntegral(gray, bw2, T, part);
     printf("%s -> %s\n", argv[1], argv[2]);
 
     // Write threshold image
-    cv::imwrite(argv[2],bw2);
+    cv::imwrite(argv[2], bw2);
     return 0;
 }