From 70644138635b87546b23a4621d9759d5652749a8 Mon Sep 17 00:00:00 2001
From: Benjamin Franzke <benjaminfranzke@googlemail.com>
Date: Fri, 30 Mar 2012 09:14:46 +0200
Subject: Add simple roi-algorithm

---
 Makefile |   5 ++--
 roi.c    | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+), 2 deletions(-)
 create mode 100644 roi.c

diff --git a/Makefile b/Makefile
index 2f72437..879d1af 100644
--- a/Makefile
+++ b/Makefile
@@ -5,13 +5,14 @@ CFLAGS = -ggdb -std=c99 -pedantic -Wall $(DEFINES) \
 LDFLAGS = $(LIBS) -lm \
 	  $(shell pkg-config --libs gdk-pixbuf-2.0 glib-2.0 gthread-2.0)
 
-PROGS = wimmel wimmel_gl
-OBJS = wimmel.o wimmel_gl.o util.o
+PROGS = wimmel wimmel_gl roi
+OBJS = wimmel.o wimmel_gl.o util.o roi.o
 
 all: $(PROGS)
 
 wimmel: wimmel.o util.o
 wimmel_gl: wimmel_gl.o util.o
+roi: roi.o
 
 .PHONY: clean all
 
diff --git a/roi.c b/roi.c
new file mode 100644
index 0000000..6e8ed74
--- /dev/null
+++ b/roi.c
@@ -0,0 +1,100 @@
+#include <stdlib.h>
+#include <glib.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <math.h>
+
+int
+main(int argc, char *argv[])
+{
+	char *file;
+	GdkPixbuf *input;
+	GdkPixbuf *match_tmp, *match;
+	int x, y, i, j;
+	int x1, y1, mwidth, mheight, width, height;
+	gint stride, nch;
+	guchar *pix, *row;
+
+	g_type_init();
+
+	if (argc < 5)
+		exit(EXIT_FAILURE);
+	
+	file = argv[1];
+	x1 = atoi(argv[2]);
+	y1 = atoi(argv[3]);
+	mwidth = atoi(argv[4]);
+	mheight = atoi(argv[5]);
+
+	input = gdk_pixbuf_new_from_file(file, NULL);
+	if (!input)
+		exit(EXIT_FAILURE);
+
+	match_tmp = gdk_pixbuf_new_subpixbuf(input, x1, y1, mwidth, mheight);
+	match = gdk_pixbuf_copy(match_tmp);
+	g_object_unref(match_tmp);
+
+	struct match_interval {
+		gint min, max;
+	} interval[3];
+
+	nch = gdk_pixbuf_get_n_channels(match);
+	stride = gdk_pixbuf_get_rowstride(match);
+	gint s = mwidth * mheight;
+
+	gint middle[3] = { 0, 0, 0 };
+	for (y = 0, row = gdk_pixbuf_get_pixels(match);
+	     y < mheight; ++y, row += stride) {
+		for (x = 0, pix = row; x < mwidth; ++x, pix += nch) {
+			for (i = 0; i < 3; ++i)
+				middle[i] += pix[i];
+		}
+	}
+	for (i = 0; i < 3; ++i)
+		middle[i] /= s;
+
+	gint sigma[3] = { 0, 0, 0 };
+	for (y = 0, row = gdk_pixbuf_get_pixels(match);
+	     y < mheight; ++y, row += stride) {
+		for (x = 0, pix = row; x < mwidth; ++x, pix += nch) {
+			for (i = 0; i < 3; ++i)
+				sigma[i] +=
+					(pix[i] - middle[i]) *
+					(pix[i] - middle[i]);
+		}
+	}
+
+	for (i = 0; i < 3; ++i)
+		sigma[i] = sqrt(sigma[i] / (s - 1));
+
+	printf("middle: %3d, %3d, %3d\n", middle[0], middle[1], middle[2]);
+	printf("sigma:  %3d, %3d, %3d\n", sigma[0], sigma[1], sigma[2]);
+
+	for (i = 0; i < 3; ++i) {
+		interval[i].min = middle[i] - 2 * sigma[i];
+		interval[i].max = middle[i] + 2 * sigma[i];
+		printf("interval %d: [%3d - %3d]\n",
+		       i, interval[i].min, interval[i].max);
+	}
+
+	nch = gdk_pixbuf_get_n_channels(input);
+	stride = gdk_pixbuf_get_rowstride(input);
+	width = gdk_pixbuf_get_width(input);
+	height = gdk_pixbuf_get_height(input);
+	for (y = 0, row = gdk_pixbuf_get_pixels(input);
+	     y < height; ++y, row += stride) {
+		for (x = 0, pix = row; x < width; ++x, pix += nch) {
+			int H = 1;
+			for (i = 0; i < 3; ++i) {
+				if (!(pix[i] >= interval[i].min &&
+				      pix[i] <= interval[i].max))
+				    H = 0;
+			}
+			if (H)
+				pix[0] = pix[1] = pix[2] = 0;
+		}
+	}
+
+	gdk_pixbuf_save(input, "output_roi.tiff", "tiff", NULL, NULL);
+	g_object_unref(input);
+	g_object_unref(match);
+}
-- 
cgit