From d97331b88ff3d50035b1e22c9d0eb671b61227e3 Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Wed, 15 Apr 2015 07:32:32 +0000
Subject: [PATCH] level adjustment for images
---
src/image.c | 172 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 163 insertions(+), 9 deletions(-)
diff --git a/src/image.c b/src/image.c
index d3fb61e..bf6ce6a 100644
--- a/src/image.c
+++ b/src/image.c
@@ -20,7 +20,7 @@
void draw_box(image a, int x1, int y1, int x2, int y2, float r, float g, float b)
{
- normalize_image(a);
+ //normalize_image(a);
int i;
if(x1 < 0) x1 = 0;
if(x1 >= a.w) x1 = a.w-1;
@@ -113,6 +113,15 @@
return dest;
}
+void constrain_image(image im)
+{
+ int i;
+ for(i = 0; i < im.w*im.h*im.c; ++i){
+ if(im.data[i] < 0) im.data[i] = 0;
+ if(im.data[i] > 1) im.data[i] = 1;
+ }
+}
+
void normalize_image(image p)
{
float *min = calloc(p.c, sizeof(float));
@@ -154,7 +163,7 @@
{
int x,y,k;
image copy = copy_image(p);
- normalize_image(copy);
+ //normalize_image(copy);
char buff[256];
//sprintf(buff, "%s (%d)", name, windows);
@@ -193,7 +202,7 @@
{
int x,y,k;
image copy = copy_image(p);
- normalize_image(copy);
+ //normalize_image(copy);
char buff[256];
//sprintf(buff, "%s (%d)", name, windows);
@@ -300,7 +309,7 @@
for(k= 0; k < c; ++k){
for(i = 0; i < h; ++i){
for(j = 0; j < w; ++j){
- out.data[count++] = data[i*step + j*c + k];
+ out.data[count++] = data[i*step + j*c + k]/255.;
}
}
}
@@ -327,6 +336,94 @@
return cropped;
}
+float three_way_max(float a, float b, float c)
+{
+ return (a > b) ? ( (a > c) ? a : c) : ( (b > c) ? b : c) ;
+}
+
+float three_way_min(float a, float b, float c)
+{
+ return (a < b) ? ( (a < c) ? a : c) : ( (b < c) ? b : c) ;
+}
+
+// http://www.cs.rit.edu/~ncs/color/t_convert.html
+void rgb_to_hsv(image im)
+{
+ assert(im.c == 3);
+ int i, j;
+ float r, g, b;
+ float h, s, v;
+ for(j = 0; j < im.h; ++j){
+ for(i = 0; i < im.w; ++i){
+ r = get_pixel(im, i , j, 2);
+ g = get_pixel(im, i , j, 1);
+ b = get_pixel(im, i , j, 0);
+ float max = three_way_max(r,g,b);
+ float min = three_way_min(r,g,b);
+ float delta = max - min;
+ v = max;
+ if(max == 0){
+ s = 0;
+ h = -1;
+ }else{
+ s = delta/max;
+ if(r == max){
+ h = (g - b) / delta;
+ } else if (g == max) {
+ h = 2 + (b - r) / delta;
+ } else {
+ h = 4 + (r - g) / delta;
+ }
+ if (h < 0) h += 6;
+ }
+ set_pixel(im, i, j, 0, h);
+ set_pixel(im, i, j, 1, s);
+ set_pixel(im, i, j, 2, v);
+ }
+ }
+}
+
+void hsv_to_rgb(image im)
+{
+ assert(im.c == 3);
+ int i, j;
+ float r, g, b;
+ float h, s, v;
+ float f, p, q, t;
+ for(j = 0; j < im.h; ++j){
+ for(i = 0; i < im.w; ++i){
+ h = get_pixel(im, i , j, 0);
+ s = get_pixel(im, i , j, 1);
+ v = get_pixel(im, i , j, 2);
+ if (s == 0) {
+ r = g = b = v;
+ } else {
+ int index = floor(h);
+ f = h - index;
+ p = v*(1-s);
+ q = v*(1-s*f);
+ t = v*(1-s*(1-f));
+ if(index == 0){
+ r = v; g = t; b = p;
+ } else if(index == 1){
+ r = q; g = v; b = p;
+ } else if(index == 2){
+ r = p; g = v; b = t;
+ } else if(index == 3){
+ r = p; g = q; b = v;
+ } else if(index == 4){
+ r = t; g = p; b = v;
+ } else {
+ r = v; g = p; b = q;
+ }
+ }
+ set_pixel(im, i, j, 2, r);
+ set_pixel(im, i, j, 1, g);
+ set_pixel(im, i, j, 0, b);
+ }
+ }
+}
+
image grayscale_image(image im)
{
assert(im.c == 3);
@@ -354,7 +451,7 @@
for(j = 0; j < fore.h; ++j){
for(i = 0; i < fore.w; ++i){
float val = alpha * get_pixel(fore, i, j, k) +
- (1 - alpha)* get_pixel(back, i, j, k);
+ (1 - alpha)* get_pixel(back, i, j, k);
set_pixel(blend, i, j, k, val);
}
}
@@ -362,18 +459,59 @@
return blend;
}
+void scale_image_channel(image im, int c, float v)
+{
+ int i, j;
+ for(j = 0; j < im.h; ++j){
+ for(i = 0; i < im.w; ++i){
+ float pix = get_pixel(im, i, j, c);
+ pix = pix*v;
+ set_pixel(im, i, j, c, pix);
+ }
+ }
+}
+
+void saturate_image(image im, float sat)
+{
+ rgb_to_hsv(im);
+ scale_image_channel(im, 1, sat);
+ hsv_to_rgb(im);
+ constrain_image(im);
+}
+
+void exposure_image(image im, float sat)
+{
+ rgb_to_hsv(im);
+ scale_image_channel(im, 2, sat);
+ hsv_to_rgb(im);
+ constrain_image(im);
+}
+
+void saturate_exposure_image(image im, float sat, float exposure)
+{
+ rgb_to_hsv(im);
+ scale_image_channel(im, 1, sat);
+ scale_image_channel(im, 2, exposure);
+ hsv_to_rgb(im);
+ constrain_image(im);
+}
+
+/*
image saturate_image(image im, float sat)
{
image gray = grayscale_image(im);
image blend = blend_image(im, gray, sat);
free_image(gray);
+ constrain_image(blend);
return blend;
}
image brightness_image(image im, float b)
{
image bright = make_image(im.w, im.h, im.c);
+ return bright;
}
+*/
float billinear_interpolate(image im, float x, float y, int c)
{
@@ -413,7 +551,6 @@
void test_resize(char *filename)
{
image im = load_image(filename, 0,0);
- translate_image(im, -128);
image small = resize_image(im, 65, 63);
image big = resize_image(im, 513, 512);
image crop = crop_image(im, 50, 10, 100, 100);
@@ -422,12 +559,29 @@
image rot2 = rotate_image(big, 3.14159265/2.);
image test = rotate_image(im, .6);
image gray = grayscale_image(im);
- image sat = saturate_image(im, 2);
- image sat2 = saturate_image(im, .5);
+
+ image sat2 = copy_image(im);
+ saturate_image(sat2, 2);
+ exposure_image(sat2, 2);
+
+ image sat5 = copy_image(im);
+ saturate_image(sat5, 2);
+ exposure_image(sat5, .5);
+
+ image exp2 = copy_image(im);
+ saturate_image(exp2, .5);
+ exposure_image(exp2, 2);
+
+ image exp5 = copy_image(im);
+ saturate_image(exp5, .5);
+ exposure_image(exp5, .5);
+
show_image(im, "original");
show_image(gray, "gray");
- show_image(sat, "sat");
show_image(sat2, "sat2");
+ show_image(sat5, "sat5");
+ show_image(exp2, "exp2");
+ show_image(exp5, "exp5");
/*
show_image(small, "smaller");
show_image(big, "bigger");
--
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