Index: /trunk/pois/src/poisMaskOps.c
===================================================================
--- /trunk/pois/src/poisMaskOps.c	(revision 3806)
+++ /trunk/pois/src/poisMaskOps.c	(revision 3806)
@@ -0,0 +1,92 @@
+/*
+ * Some utility routines that should be in psLib
+ */
+#include <stdio.h>
+#include <memory.h>
+#include <assert.h>
+#include "pslib.h"
+#include "pois.h"
+
+psImage *poisImageSetVal(psImage *restrict in,	     // Input image
+			 const psC64 val	     // set to this value
+    )
+{
+    assert (in != NULL);
+
+    switch (in->type.type) {
+      case PS_TYPE_U8:
+	{
+	    const int numCols = in->numCols;
+	    psU8 *row0 = in->data.U8[0];
+	    for (int c = 0; c < numCols; c++) {
+		row0[c] = val;
+	    }
+	    for (int r = 1; r < in->numRows; r++) {
+		memcpy(in->data.U8[r], row0, numCols*sizeof(psU8));
+	    }
+	}
+	break;
+      case PS_TYPE_F32:
+	{
+	    const int numCols = in->numCols;
+	    psF32 *row0 = in->data.F32[0];
+	    for (int c = 0; c < numCols; c++) {
+		row0[c] = val;
+	    }
+	    for (int r = 1; r < in->numRows; r++) {
+		memcpy(in->data.F32[r], row0, numCols*sizeof(psF32));
+	    }
+	}
+	break;
+      default:
+	psError(POIS_ERR_UNSUPPORTED_TYPE, true,
+		"Type %d is not supported", in->type.type);
+	return NULL;
+    }
+
+    return in;
+}
+
+psImage *poisImageSetValInMask(psImage *out,			// Image to update, or NULL
+			       const psImage *restrict in,	// Input image
+			       const psImage *mask,		// mask for image
+			       const psC64 val,			// set to this value
+			       const unsigned long bits		// set pixels where mask & bits != 0
+    )
+{
+    assert(mask != NULL);
+    assert(mask->type.type == PS_TYPE_U8);
+    const int numCols = mask->numCols;
+    const int numRows = mask->numRows;
+    assert(in != NULL);
+    assert(in->type.type == PS_TYPE_F32);
+    assert(in->numCols == numCols && in->numRows == numRows);
+
+    // Allocate the output image, if necessary
+    if (out == NULL) {
+	out = psImageCopy(NULL, in, in->type.type);
+    }
+
+    switch (in->type.type) {
+      case PS_TYPE_F32:
+	{
+	    const int numCols = in->numCols;
+	    for (int r = 0; r < in->numRows; r++) {
+		psF32 *row = out->data.F32[r]; // n.b. a copy of in
+		psU8 *mrow = mask->data.U8[r];
+		for (int c = 0; c < numCols; c++) {
+		    if (mrow[c] & bits) {
+			row[c] = val;
+		    }
+		}
+	    }
+	}
+	break;
+      default:
+	psError(POIS_ERR_UNSUPPORTED_TYPE, true,
+		"Type %d is not supported", in->type.type);
+	return NULL;
+    }
+
+    return out;
+}