Changeset 25694

Timestamp:

Sep 30, 2009, 2:33:50 PM (17 years ago)

Author:

eugene

Message:

add a function to repair NAN pixels in a psImageMap

Location:

branches/eam_branches/20090715/psLib/src/imageops

Files:

• psImageMapFit.c (modified) (2 diffs)
• psImageMapFit.h (modified) (1 diff)

branches/eam_branches/20090715/psLib/src/imageops/psImageMapFit.c

@@ -33 +33 @@
 #include "psStats.h"
 #include "psImageBinning.h"
+#include "psImageStructManip.h"
 #include "psImageMap.h"
 // #include "psImagePixelInterpolate.h"
@@ -752 +753 @@
 }
 
+// this function repairs an image with NAN pixels (only valid for a small-scale map -- no robust mean)
+bool psImageMapRepair (psImage *image) {
+
+    // we are going to repair the image by:
+    // 1) finding NAN pixels
+    // 2) if any of the neighbors are valid,
+    //    replace with the mean of the neighbors
+    // 3) otherwise, replace with the image mean
+
+    // copy the image so the repaired pixels do not affect the input
+    psImage *fixed = psImageCopy (NULL, image, PS_TYPE_F32);
+
+    // find the global mean
+    float mean = 0.0;
+    float npix = 0.0;
+    for (int iy = 0; iy < image->numRows; iy++) {
+        for (int ix = 0; ix < image->numCols; ix++) {
+            if (!isfinite(image->data.F32[iy][ix])) continue;
+            mean += image->data.F32[iy][ix];
+            npix += 1.0;
+        }
+    }
+    mean /= npix;
+
+    // find the NAN pixels:
+    for (int iy = 0; iy < image->numRows; iy++) {
+        for (int ix = 0; ix < image->numCols; ix++) {
+            if (isfinite(image->data.F32[iy][ix])) {
+                fixed->data.F32[iy][ix] = image->data.F32[iy][ix];
+                continue;
+            }
+
+            // find mean of all possible neighbors
+            float meanLocal = 0.0;
+            float npixLocal = 0.0;
+            for (int jy = -1; jy <= +1; jy++) {
+                int ny = iy + jy;
+                if (ny < 0) continue;
+                if (ny >= image->numRows) continue;
+                for (int jx = -1; jx <= +1; jx++) {
+                    int nx = ix + jx;
+                    if (nx < 0) continue;
+                    if (nx >= image->numCols) continue;
+                    if (!isfinite(image->data.F32[ny][nx])) continue;
+                    meanLocal += image->data.F32[ny][nx];
+                    npixLocal += 1.0;
+                }
+            }
+            meanLocal = (npixLocal > 0.0) ? meanLocal / npixLocal : mean;
+            fixed->data.F32[iy][ix] = meanLocal;
+        }
+    }
+    
+    // find the NAN pixels:
+    for (int iy = 0; iy < image->numRows; iy++) {
+        for (int ix = 0; ix < image->numCols; ix++) {
+            image->data.F32[iy][ix] = fixed->data.F32[iy][ix];
+        }
+    }
+    psFree (fixed);
+
+    return true;
+}

branches/eam_branches/20090715/psLib/src/imageops/psImageMapFit.h

@@ -46 +46 @@
     );
 
+bool psImageMapRepair (psImage *image);
+
 #endif