Pipette and "On Preview Widgets" branch. See issue 227

The pipette part is already working quite nice but need to be finished. The widgets part needs more work...

rtengine/klt/klt_util.h

@@ -0,0 +1,37 @@
+/*********************************************************************
+ * klt_util.h
+ *********************************************************************/
+
+#ifndef _KLT_UTIL_H_
+#define _KLT_UTIL_H_
+
+typedef struct  {
+  int ncols;
+  int nrows;
+  float *data;
+}  _KLT_FloatImageRec, *_KLT_FloatImage;
+
+_KLT_FloatImage _KLTCreateFloatImage(
+  int ncols, 
+  int nrows);
+
+void _KLTFreeFloatImage(
+  _KLT_FloatImage);
+	
+void _KLTPrintSubFloatImage(
+  _KLT_FloatImage floatimg,
+  int x0, int y0,
+  int width, int height);
+
+void _KLTWriteFloatImageToPGM(
+  _KLT_FloatImage img,
+  const char *filename);
+
+/* for affine mapping */
+void _KLTWriteAbsFloatImageToPGM(
+  _KLT_FloatImage img,
+  const char *filename,float scale);
+
+#endif
+
+