I need to read an image file in C/C++. It would be very great, if some one can post the code for me.
I work on gray scale images and the images are JPEG. I would like to read the images into a 2D array which will make my work easy.
7 Answers
You could write your own by looking at the JPEG format.
That said, try a pre-existing library like CImg, or Boost's GIL. Or for strictly JPEG's, libjpeg. There is also the CxImage class on CodeProject.
Here's a big list.
Check this thread out: read and write image file.
Also, have a look at this other question at Stackoverflow.
corona is nice. From the tutorial:
corona::Image* image = corona::OpenImage("img.jpg", corona::PF_R8G8B8A8);
if (!image) {
// error!
}
int width = image->getWidth();
int height = image->getHeight();
void* pixels = image->getPixels();
// we're guaranteed that the first eight bits of every pixel is red,
// the next eight bits is green, and so on...
typedef unsigned char byte;
byte* p = (byte*)pixels;
for (int i = 0; i < width * height; ++i) {
byte red = *p++;
byte green = *p++;
byte blue = *p++;
byte alpha = *p++;
}
pixels would be a one dimensional array, but you could easily convert a given x and y position to a position in a 1D array. Something like pos = (y * width) + x
Related