From 8ed0a5538e04002c95ff0757791c52b4ec9a3e96 Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Tue, 21 Jul 2015 18:38:36 +0000
Subject: [PATCH] faster resize?
---
src/image.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/src/image.c b/src/image.c
index 046de0c..c499c79 100644
--- a/src/image.c
+++ b/src/image.c
@@ -584,6 +584,51 @@
return resized;
}
+image resize_image2(image im, int w, int h)
+{
+ image resized = make_image(w, h, im.c);
+ image part = make_image(w, im.h, im.c);
+ int r, c, k;
+ float w_scale = (float)(im.w - 1) / (w - 1);
+ float h_scale = (float)(im.h - 1) / (h - 1);
+ for(k = 0; k < im.c; ++k){
+ for(r = 0; r < im.h; ++r){
+ for(c = 0; c < w; ++c){
+ float val = 0;
+ if(c == w-1){
+ val = get_pixel(im, im.w-1, r, k);
+ } else {
+ float sx = c*w_scale;
+ int ix = (int) sx;
+ float dx = sx - ix;
+ val = (1 - dx) * get_pixel(im, ix, r, k) + dx * get_pixel(im, ix+1, r, k);
+ }
+ set_pixel(part, c, r, k, val);
+ }
+ }
+ }
+
+ for(k = 0; k < im.c; ++k){
+ for(r = 0; r < h; ++r){
+ float sy = r*h_scale;
+ int iy = (int) sy;
+ float dy = sy - iy;
+ for(c = 0; c < w; ++c){
+ float val = (1-dy) * get_pixel(part, c, iy, k);
+ set_pixel(resized, c, r, k, val);
+ }
+ if(r == h-1) continue;
+ for(c = 0; c < w; ++c){
+ float val = dy * get_pixel(part, c, iy+1, k);
+ add_pixel(resized, c, r, k, val);
+ }
+ }
+ }
+
+ free_image(part);
+ return resized;
+}
+
void test_resize(char *filename)
{
image im = load_image(filename, 0,0, 3);
@@ -728,6 +773,11 @@
assert(x < m.w && y < m.h && c < m.c);
m.data[c*m.h*m.w + y*m.w + x] = val;
}
+void add_pixel(image m, int x, int y, int c, float val)
+{
+ assert(x < m.w && y < m.h && c < m.c);
+ m.data[c*m.h*m.w + y*m.w + x] += val;
+}
void print_image(image m)
{
--
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