在前面一篇,已经能够基于gtk读取图像并显示。更前面的一篇:基于GDI的imshow:使用stb_image读取图像并修正绘制,通过stb_image读取图像并通过GDI显示图像,实现了一个imshow。本篇则在这两基础上,利用stb_image读取图像,并利用gtk显示,初步实现一个基于gtk的imshow。
首先是找到一份代码,从指定的buffer创建gtk的image并显示(参考1)。然后用stb image读取,先前我进行了封装,得到fc image是和opencv兼容的bgr格式。然而发现gtk需要的是rgb的顺序,因此又做了一道转化步骤:BGR to RGB,然后把对应的buffer传给gtk去生成它的image。
代码实现
完整的代码需要 基于GDI的imshow:使用stb_image读取图像并修正绘制 这一篇blog中的代码,以及本文新增的代码gtk_show_image_v3.c
:
#include <gtk/gtk.h>
#include <stdlib.h>
#include <assert.h>
#include "fc_image.h"
void fc_bgr_to_rgb(FcImage* im) {
if (im==NULL) return;
if (im->c<=0 || im->h<=0 || im->w==0) return;
assert(im->c==3);
int num_pixel = im->c * im->h * im->w;
unsigned char t;
for(int i=0; i<num_pixel; i+=3) {
t = im->data[i];
im->data[i] = im->data[i+2];
im->data[i+2] = t;
}
}
int main (int argc, char *argv[])
{
const char* im_pth = "/home/zz/work/libfc/imgs/fruits.jpg";
FcImage im = fc_load_image(im_pth);
fc_bgr_to_rgb(&im);
GtkWidget *window;
GtkWidget* image;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
GdkPixbuf *pixbuf = gdk_pixbuf_new_from_data (im.data, GDK_COLORSPACE_RGB,
FALSE, 8, im.w, im.h, im.w*3, NULL, NULL);
gtk_window_set_title (GTK_WINDOW (window), "Image Viewer");
g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
image = gtk_image_new_from_pixbuf (pixbuf);
gtk_container_add(GTK_CONTAINER (window), image);
gtk_widget_show_all (window);
gtk_main ();
return 0;
}
简单封装
考虑到把原有的bgr顺序的图像buffer修改为rgb,就地修改肯定是有问题的,影响到后续算法的使用。因此应当拷贝产生一个新的图像数据。并且还需要把im和title作为参数,封装为API,以后调用方便。修改后的代码如下:
#include <gtk/gtk.h>
#include <stdlib.h>
#include <assert.h>
#include "fc_image.h"
void fc_copy_bgr_to_rgb(const FcImage* src, FcImage* dst) {
if (src==NULL) return;
if (dst==NULL) return;
assert(src!=dst);
assert(src->data!=NULL);
assert(dst->data!=NULL);
assert(src->data!=dst->data);
assert(src->c>=0 && src->h>=0 && src->c==3);
assert(src->c>=0 && src->h>=0 && src->c==3);
assert(src->c==dst->c && src->h==dst->h && src->w==dst->w);
int num_pixel = src->c * src->h * src->w;
for(int i=0; i<num_pixel; i+=3) {
dst->data[i] = src->data[i+2];
dst->data[i+1] = src->data[i+1];
dst->data[i+2] = src->data[i];
}
}
FcImage fc_make_image(int w, int h, int c)
{
FcImage out;
out.w = w;
out.h = h;
out.c = c;
out.data = (unsigned char*)calloc(h*w*c, sizeof(float));
return out;
}
void gtk_show_image_v3(const FcImage* im, const char* title)
{
FcImage im_rgb = fc_make_image(im->w, im->h, im->c); //?? check this dimensions
fc_copy_bgr_to_rgb(im, &im_rgb);
GtkWidget *window;
GtkWidget* image;
gtk_init (NULL, NULL);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
GdkPixbuf *pixbuf = gdk_pixbuf_new_from_data (im_rgb.data, GDK_COLORSPACE_RGB,
FALSE, 8, im_rgb.w, im_rgb.h, im_rgb.w*3, NULL, NULL);
gtk_window_set_title (GTK_WINDOW (window), title);
g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
image = gtk_image_new_from_pixbuf (pixbuf);
gtk_container_add(GTK_CONTAINER (window), image);
gtk_widget_show_all (window);
gtk_main ();
}
int main (int argc, char *argv[])
{
const char* im_pth = "/home/zz/work/libfc/imgs/fruits.jpg";
FcImage im = fc_load_image(im_pth);
const char* title = "fruits";
gtk_show_image_v3(&im, title);
return 0;
}
参考
Display a sequence of images using gtk in Linux
原文地址:https://www.cnblogs.com/zjutzz/p/10960235.html
时间: 2024-11-05 22:02:38