Changeset 19383 for trunk/psLib/src/fits/psFitsScale.c

Timestamp:

Sep 4, 2008, 9:51:09 PM (18 years ago)

Author:

Paul Price

Message:

Adding capability for a mask to be provided when determining BSCALE,BZERO. This is required for the case when a large masked region of the image has been set to a constant (or close to a constant). If the mask is not provided in this case, then the standard deviation is under-estimated, leading to a choice of BSCALE,BZERO that adversely affects the dynamic range of the image. Added functions psFitsWriteImageWithMask, psFitsUpdateImageWithMask and psFitsInsertImageWithMask, and kept the APIs of psFitsWriteImage, psFitsUpdateImage and psFitsInsertImage so that this change shouldn't break anything.

File:

• trunk/psLib/src/fits/psFitsScale.c (modified) (6 diffs)

trunk/psLib/src/fits/psFitsScale.c

@@ -13 +13 @@
 #include "psTrace.h"
 
+#include "psImage.h"
 #include "psFits.h"
 #include "psImageBackground.h"
@@ -98 +99 @@
                        double *bzero, // Zero point, to return
                        const psImage *image, // Image to scale
+                       const psImage *mask, // Mask image
+                       psMaskType maskVal, // Value to mask
                        const psFitsOptions *options // FITS options
     )
@@ -112 +115 @@
     psRandom *rng = psRandomAlloc(PS_RANDOM_TAUS, seed);
     psStats *stats = psStatsAlloc(MEAN_STAT | STDEV_STAT); // Statistics object
-    if (!psImageBackground(stats, NULL, image, NULL, 0, rng)) {
+    if (!psImageBackground(stats, NULL, image, mask, maskVal, rng)) {
         psError(PS_ERR_UNKNOWN, false, "Unable to perform statistics on image");
         psFree(rng);
@@ -163 +166 @@
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-bool psFitsScaleDetermine(double *bscale, // Scaling, to return
-                          double *bzero, // Zero point, to return
-                          long *blank,  // Blank value, to return
-                          const psImage *image, // Image to scale
-                          const psFits *fits // FITS options
-    )
+bool psFitsScaleDetermine(double *bscale, double *bzero, long *blank, const psImage *image,
+                          const psImage *mask, psMaskType maskVal, const psFits *fits)
 {
     PS_ASSERT_PTR_NON_NULL(bscale, false);
@@ -174 +173 @@
     PS_ASSERT_PTR_NON_NULL(blank, false);
     PS_ASSERT_IMAGE_NON_NULL(image, false);
+    if (mask) {
+        PS_ASSERT_IMAGE_TYPE(mask, PS_TYPE_MASK, false);
+        PS_ASSERT_IMAGES_SIZE_EQUAL(mask, image, false);
+    }
     PS_ASSERT_FITS_NON_NULL(fits, false);
 
@@ -216 +219 @@
       case PS_FITS_SCALE_STDEV_NEGATIVE:
       case PS_FITS_SCALE_STDEV_BOTH:
-        if (!scaleStdev(bscale, bzero, image, options)) {
+        if (!scaleStdev(bscale, bzero, image, mask, maskVal, options)) {
             psError(PS_ERR_UNKNOWN, false, "Unable to set BSCALE and BZERO from stdev");
             return false;