--- /dev/null
+/*
+ * EffecTV - Realtime Digital Video Effector
+ * Copyright (C) 2001-2006 FUKUCHI Kentaro
+ *
+ * image.c: utilities for image processing.
+ *
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include "utils.h"
+
+
+/*
+ * Collection of background subtraction functions
+ */
+
+/* checks only fake-Y value */
+/* In these function Y value is treated as R*2+G*4+B. */
+
+int image_set_threshold_y(int threshold)
+{
+ int y_threshold = threshold * 7; /* fake-Y value is timed by 7 */
+
+ return y_threshold;
+}
+
+void image_bgset_y(RGB32 *background, const RGB32 *src, int video_area, int y_threshold)
+{
+ int i;
+ int R, G, B;
+ const RGB32 *p;
+ short *q;
+
+ p = src;
+ q = (short *)background;
+ for(i=0; i<video_area; i++) {
+ /* FIXME: endianess */
+
+ R = ((*p)&0xff0000)>>(16-1);
+ G = ((*p)&0xff00)>>(8-2);
+ B = (*p)&0xff;
+ *q = (short)(R + G + B);
+ p++;
+ q++;
+ }
+}
+
+void image_bgsubtract_y(unsigned char *diff, const RGB32 *background, const RGB32 *src, int video_area, int y_threshold)
+{
+ int i;
+ int R, G, B;
+ const RGB32 *p;
+ short *q;
+ unsigned char *r;
+ int v;
+
+ p = src;
+ q = (short *)background;
+ r = diff;
+ for(i=0; i<video_area; i++) {
+ /* FIXME: endianess */
+
+ R = ((*p)&0xff0000)>>(16-1);
+ G = ((*p)&0xff00)>>(8-2);
+ B = (*p)&0xff;
+ v = (R + G + B) - (int)(*q);
+ *r = ((v + y_threshold)>>24) | ((y_threshold - v)>>24);
+
+ p++;
+ q++;
+ r++;
+ }
+
+/* The origin of subtraction function is;
+ * diff(src, dest) = (abs(src - dest) > threshold) ? 0xff : 0;
+ *
+ * This functions is transformed to;
+ * (threshold > (src - dest) > -threshold) ? 0 : 0xff;
+ *
+ * (v + threshold)>>24 is 0xff when v is less than -threshold.
+ * (v - threshold)>>24 is 0xff when v is less than threshold.
+ * So, ((v + threshold)>>24) | ((threshold - v)>>24) will become 0xff when
+ * abs(src - dest) > threshold.
+ */
+}
+
+/* Background image is refreshed every frame */
+void image_bgsubtract_update_y(unsigned char *diff, RGB32 *background, const RGB32 *src, int video_area, int y_threshold)
+{
+ int i;
+ int R, G, B;
+ const RGB32 *p;
+ short *q;
+ unsigned char *r;
+ int v;
+
+ p = src;
+ q = (short *)background;
+ r = diff;
+ for(i=0; i<video_area; i++) {
+ /* FIXME: endianess */
+
+ R = ((*p)&0xff0000)>>(16-1);
+ G = ((*p)&0xff00)>>(8-2);
+ B = (*p)&0xff;
+ v = (R + G + B) - (int)(*q);
+ *q = (short)(R + G + B);
+ *r = ((v + y_threshold)>>24) | ((y_threshold - v)>>24);
+
+ p++;
+ q++;
+ r++;
+ }
+}
+
+/* checks each RGB value */
+
+/* The range of r, g, b are [0..7] */
+RGB32 image_set_threshold_RGB(int r, int g, int b)
+{
+ unsigned char R, G, B;
+ RGB32 rgb_threshold;
+
+ R = G = B = 0xff;
+ R = R<<r;
+ G = G<<g;
+ B = B<<b;
+ rgb_threshold = (RGB32)(R<<16 | G<<8 | B);
+
+ return rgb_threshold;
+}
+
+void image_bgset_RGB(RGB32 *background, const RGB32 *src, int video_area)
+{
+ int i;
+ RGB32 *p;
+
+ p = background;
+ for(i=0; i<video_area; i++) {
+ *p++ = (*src++) & 0xfefefe;
+ }
+}
+
+void image_bgsubtract_RGB(unsigned char *diff, const RGB32 *background, const RGB32 *src, int video_area, RGB32 rgb_threshold)
+{
+ int i;
+ const RGB32 *p, *q;
+ unsigned a, b;
+ unsigned char *r;
+
+ p = src;
+ q = background;
+ r = diff;
+ for(i=0; i<video_area; i++) {
+ a = (*p++)|0x1010100;
+ b = *q++;
+ a = a - b;
+ b = a & 0x1010100;
+ b = b - (b>>8);
+ b = b ^ 0xffffff;
+ a = a ^ b;
+ a = a & rgb_threshold;
+ *r++ = (0 - a)>>24;
+ }
+}
+
+void image_bgsubtract_update_RGB(unsigned char *diff, RGB32 *background, const RGB32 *src, int video_area, RGB32 rgb_threshold)
+{
+ int i;
+ const RGB32 *p;
+ RGB32 *q;
+ unsigned a, b;
+ unsigned char *r;
+
+ p = src;
+ q = background;
+ r = diff;
+ for(i=0; i<video_area; i++) {
+ a = *p|0x1010100;
+ b = *q&0xfefefe;
+ *q++ = *p++;
+ a = a - b;
+ b = a & 0x1010100;
+ b = b - (b>>8);
+ b = b ^ 0xffffff;
+ a = a ^ b;
+ a = a & rgb_threshold;
+ *r++ = (0 - a)>>24;
+ }
+}
+
+/* noise filter for subtracted image. */
+void image_diff_filter(unsigned char *diff2, const unsigned char *diff, int width, int height)
+{
+ int x, y;
+ const unsigned char *src;
+ unsigned char *dest;
+ unsigned int count;
+ unsigned int sum1, sum2, sum3;
+
+ src = diff;
+ dest = diff2 + width +1;
+ for(y=1; y<height-1; y++) {
+ sum1 = src[0] + src[width] + src[width*2];
+ sum2 = src[1] + src[width+1] + src[width*2+1];
+ src += 2;
+ for(x=1; x<width-1; x++) {
+ sum3 = src[0] + src[width] + src[width*2];
+ count = sum1 + sum2 + sum3;
+ sum1 = sum2;
+ sum2 = sum3;
+ *dest++ = (0xff*3 - count)>>24;
+ src++;
+ }
+ dest += 2;
+ }
+}
+
+/* Y value filters */
+void image_y_over(unsigned char *diff, const RGB32 *src, int video_area, int y_threshold)
+{
+ int i;
+ int R, G, B, v;
+ unsigned char *p = diff;
+
+ for(i = video_area; i>0; i--) {
+ R = ((*src)&0xff0000)>>(16-1);
+ G = ((*src)&0xff00)>>(8-2);
+ B = (*src)&0xff;
+ v = y_threshold - (R + G + B);
+ *p = (unsigned char)(v>>24);
+ src++;
+ p++;
+ }
+}
+
+void image_y_under(unsigned char *diff, const RGB32 *src, int video_area, int y_threshold)
+{
+ int i;
+ int R, G, B, v;
+ unsigned char *p = diff;
+
+ for(i = video_area; i>0; i--) {
+ R = ((*src)&0xff0000)>>(16-1);
+ G = ((*src)&0xff00)>>(8-2);
+ B = (*src)&0xff;
+ v = (R + G + B) - y_threshold;
+ *p = (unsigned char)(v>>24);
+ src++;
+ p++;
+ }
+}
+
+/* tiny edge detection */
+void image_edge(unsigned char *diff2, const RGB32 *src, int width, int height, int y_threshold)
+{
+ int x, y;
+ unsigned char *p, *q;
+ int r, g, b;
+ int ar, ag, ab;
+ int w;
+
+ p = (unsigned char *)src;
+ q = diff2;
+ w = width * sizeof(RGB32);
+
+ for(y=0; y<height - 1; y++) {
+ for(x=0; x<width - 1; x++) {
+ b = p[0];
+ g = p[1];
+ r = p[2];
+ ab = abs(b - p[4]);
+ ag = abs(g - p[5]);
+ ar = abs(r - p[6]);
+ ab += abs(b - p[w]);
+ ag += abs(g - p[w+1]);
+ ar += abs(r - p[w+2]);
+ b = ab+ag+ar;
+ if(b > y_threshold) {
+ *q = 255;
+ } else {
+ *q = 0;
+ }
+ q++;
+ p += 4;
+ }
+ p += 4;
+ *q++ = 0;
+ }
+ memset(q, 0, width);
+}
+
+/* horizontal flipping */
+void image_hflip(const RGB32 *src, RGB32 *dest, int width, int height)
+{
+ int x, y;
+
+ src += width - 1;
+ for(y=0; y<height; y++) {
+ for(x=0; x<width; x++) {
+ *dest++ = *src--;
+ }
+ src += width * 2;
+ }
+}
+
projects / melted / blobdiff