* Preliminary image histogram routines and example

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2809 92316355-f0b4-4df1-b90c-862c8a59935f

examples/Makefile.am

@@ -2,7 +2,7 @@
 
 AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/pipi
 
-bin_PROGRAMS = edd img2rubik sharpen floodfill line bezier
+bin_PROGRAMS = edd img2rubik sharpen floodfill line bezier histogram
 
 edd_SOURCES = edd.c
 edd_LDADD = ../pipi/libpipi.la
@@ -21,3 +21,6 @@ line_LDADD = ../pipi/libpipi.la
 
 bezier_SOURCES = bezier.c
 bezier_LDADD = ../pipi/libpipi.la
+
+histogram_SOURCES = histogram.c
+histogram_LDADD = ../pipi/libpipi.la

examples/histogram.c

@@ -0,0 +1,49 @@
+#include "config.h"
+#include "common.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <pipi.h>
+
+int main(int argc, char *argv[])
+{
+    char *srcname = NULL, *dstname = NULL;
+    pipi_image_t *img, *newimg, *tmp;
+    pipi_histogram_t* histogram;
+    int ret = 0;
+    if(argc < 2)
+    {
+        fprintf(stderr, "%s: too few arguments\n", argv[0]);
+        fprintf(stderr, "Usage: %s <src> <dest>\n", argv[0]);
+        return EXIT_FAILURE;
+    }
+
+    srcname = argv[1];
+    dstname = argv[2];
+
+    img = pipi_load(srcname);
+
+    if(!img) {
+        fprintf(stderr, "Can't open %s for reading\n", srcname);
+    }
+
+    newimg = pipi_copy(img);
+    pipi_free(img);
+
+
+    tmp = pipi_copy(newimg);
+
+    histogram = pipi_new_histogram();
+    pipi_get_image_histogram(tmp, histogram, PIPI_COLOR_R|PIPI_COLOR_G|PIPI_COLOR_B);
+
+
+    pipi_render_histogram(tmp, histogram, PIPI_COLOR_R|PIPI_COLOR_G|PIPI_COLOR_B);
+
+    pipi_save(tmp, dstname);
+    pipi_free(newimg);
+
+    return ret;
+}
+

pipi/Makefile.am

@@ -31,6 +31,7 @@ libpipi_la_SOURCES = \
 	$(filter_sources) \
 	$(quantize_sources) \
 	$(dither_sources) \
+	$(histogram_sources) \
 	$(NULL)
 libpipi_la_CFLAGS = $(codec_cflags)
 libpipi_la_LDFLAGS = $(codec_libs) \
@@ -79,6 +80,9 @@ dither_sources = \
 	dither/dbs.c \
 	dither/random.c
 
+histogram_sources = \
+	histogram/histogram.c
+
 if USE_SDL
 codec_cflags += `sdl-config --cflags`
 codec_libs += `sdl-config --libs` -lSDL_image

pipi/histogram/histogram.c

@@ -0,0 +1,171 @@
+/*
+ *  libpipi       Proper image processing implementation library
+ *  Copyright (c) 2004-2008 Sam Hocevar <sam@zoy.org>
+ *                2008 Jean-Yves Lamoureux <jylam@lnxscene.org
+ *                All Rights Reserved
+ *
+ *  $Id$
+ *
+ *  This library is free software. It comes without any warranty, to
+ *  the extent permitted by applicable law. You can redistribute it
+ *  and/or modify it under the terms of the Do What The Fuck You Want
+ *  To Public License, Version 2, as published by Sam Hocevar. See
+ *  http://sam.zoy.org/wtfpl/COPYING for more details.
+ */
+
+/*
+ * histogram.c: histogram functions
+ */
+
+#include "config.h"
+#include "common.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "pipi.h"
+#include "pipi_internals.h"
+
+
+pipi_histogram_t* pipi_new_histogram(void)
+{
+    return malloc(sizeof(pipi_histogram_t));
+}
+
+
+int pipi_get_image_histogram(pipi_image_t *img, pipi_histogram_t*h, int flags)
+{
+    int i;
+
+    if(!h) return -1;
+
+    uint8_t  *data = (uint8_t *)pipi_getpixels(img, PIPI_PIXELS_RGBA_C)->pixels;
+
+    for(i=0; i< img->w*img->h*4; i+=4)
+    {
+        if(flags&PIPI_COLOR_A)
+        h->a[data[i+3]]++;
+        if(flags&PIPI_COLOR_R)
+        h->r[data[i+2]]++;
+        if(flags&PIPI_COLOR_G)
+        h->g[data[i+1]]++;
+        if(flags&PIPI_COLOR_B)
+        h->b[data[i]]++;
+        if(flags&PIPI_COLOR_Y)
+        {
+            uint32_t p = 0.;
+            p += 0.299 * data[i];
+            p += 0.587 * data[i+1];
+            p += 0.114 * data[i+2];
+
+            h->y[p>255?255:p]++;
+        }
+    }
+
+    /* Normalize dataset */
+    unsigned int max;
+    float n;
+
+    if(flags&PIPI_COLOR_R)
+    {
+        max = 0;
+        for(i=0; i<256; i++)
+            if(h->r[i] > max) max = h->r[i];
+        n = 255.0f / max;
+        for(i=0; i<256; i++)
+            h->r[i]*=n;
+    }
+    if(flags&PIPI_COLOR_G)
+    {
+        max = 0;
+        for(i=0; i<256; i++)
+            if(h->g[i] > max) max = h->g[i];
+        n = 255.0f / max;
+        for(i=0; i<256; i++)
+            h->g[i]*=n;
+    }
+    if(flags&PIPI_COLOR_B)
+    {
+        max = 0;
+        for(i=0; i<256; i++)
+            if(h->b[i] > max) max = h->b[i];
+        n = 255.0f / max;
+        for(i=0; i<256; i++)
+            h->b[i]*=n;
+    }
+    if(flags&PIPI_COLOR_A)
+    {
+        max = 0;
+        for(i=0; i<256; i++)
+            if(h->a[i] > max) max = h->a[i];
+        n = 255.0f / max;
+        for(i=0; i<256; i++)
+            h->a[i]*=n;
+    }
+    if(flags&PIPI_COLOR_Y)
+    {
+        max = 0;
+        for(i=0; i<256; i++)
+            if(h->y[i] > max) max = h->y[i];
+        n = 255.0f / max;
+        for(i=0; i<256; i++)
+            h->y[i]*=n;
+    }
+
+
+    return 0;
+}
+
+int pipi_render_histogram(pipi_image_t *img, pipi_histogram_t*h, int flags)
+{
+    if(!img || !h) return -1;
+
+    int x;
+
+
+    for(x=0; x<256; x++)
+    {
+        if(flags&PIPI_COLOR_R)
+            pipi_draw_line(img,
+                           x, 255,
+                           x, 255 - h->r[x],
+                           0x00FF0000,
+                           0);
+        if(flags&PIPI_COLOR_G)
+            pipi_draw_line(img,
+                           x, 255,
+                           x, 255 - h->g[x],
+                           0x0000FF00,
+                           0);
+        if(flags&PIPI_COLOR_B)
+            pipi_draw_line(img,
+                           x, 255,
+                           x, 255 - h->b[x],
+                           0x000000FF,
+                           0);
+        if(flags&PIPI_COLOR_A)
+            pipi_draw_line(img,
+                           x, 255,
+                           x, 255 - h->a[x],
+                           0x00000FFF,
+                           0);
+        if(flags&PIPI_COLOR_Y)
+            pipi_draw_line(img,
+                           x, 255,
+                           x, 255 - h->y[x],
+                           0x00FFFFFF,
+                           0);
+    }
+
+    return 0;
+}
+
+
+int pipi_free_histogram(pipi_histogram_t* h)
+{
+    if(h) free(h);
+    else  return -1;
+
+    return 0;
+}

pipi/pipi.h

@@ -54,6 +54,17 @@ typedef enum
 }
 pipi_format_t;
 
+
+typedef enum
+{
+    PIPI_COLOR_R = 1,
+    PIPI_COLOR_G = 2,
+    PIPI_COLOR_B = 4,
+    PIPI_COLOR_A = 8,
+    PIPI_COLOR_Y = 16
+}
+pipi_color_flag_t;
+
 struct pixel_u32
 {
     uint8_t r, g, b, a;
@@ -88,6 +99,8 @@ typedef struct pipi_image pipi_image_t;
 /* pipi_context_t: the processing stack */
 typedef struct pipi_context pipi_context_t;
 
+/* pipi_histogram_t: the histogram type */
+typedef struct pipi_histogram pipi_histogram_t;
 
 extern pipi_context_t *pipi_create_context(void);
 extern void pipi_destroy_context(pipi_context_t *);
@@ -170,6 +183,11 @@ extern pipi_image_t *pipi_dither_ostromoukhov(pipi_image_t *, pipi_scan_t);
 extern pipi_image_t *pipi_dither_dbs(pipi_image_t *);
 extern void pipi_dither_24to16(pipi_image_t *);
 
+extern pipi_histogram_t* pipi_new_histogram(void);
+extern int pipi_get_image_histogram(pipi_image_t *, pipi_histogram_t *, int);
+extern int pipi_free_histogram(pipi_histogram_t*);
+extern int pipi_render_histogram(pipi_image_t *, pipi_histogram_t*, int);
+
 
 #ifdef __cplusplus
 }

pipi/pipi_internals.h

@@ -23,6 +23,17 @@
 #define SET_FLAG_WRAP 0x00000002
 #define SET_FLAG_8BIT 0x00000004
 
+struct pipi_histogram
+{
+    int r_present, g_present, b_present, y_present;
+    unsigned int a[256];
+    unsigned int r[256];
+    unsigned int g[256];
+    unsigned int b[256];
+    unsigned int y[256];
+};
+
+
 /* pipi_image_t: the image structure. This is probably going to be the most
  * complex structure in the library, but right now it only has fairly normal
  * stuff, like width and height and pointers to pixel areas. */