counting negative values

lib/fimg-math.c

@@ -108,6 +108,27 @@ for (idx=0; idx<nbre; idx++) {
 	}
 }
 /* ---------------------------------------------------------------- */
+int fimg_count_negativ(FloatImg *fi)
+{
+int		nbre, idx;
+int		count;
+
+if (fi->type != FIMG_TYPE_RGB) {
+	fprintf(stderr, "%s : type %d invalide\n",
+				__func__, fi->type);
+	return -1;
+	}
+
+nbre = fi->width * fi->height * fi->type;
+
+count = 0;
+for (idx=0; idx<nbre; idx++) {
+	if (fi->R[idx] < 0.0) count++;
+	}
+
+return count;
+}
+/* ---------------------------------------------------------------- */
 void  fimg_mul_cste(FloatImg *fi, float value)
 {
 int		nbre, idx;