How to declare a variable size 2D array in C?

Question

I have a problem with a project. I have to make a variable size 2D array for storing some prediction error..so this is about images. The trouble is that I have to load image

Answer 1

If you have a modern C compiler (at least C99) in function scope it is as simple as:

unsigned arr[n][m];

this is called a variable length array (VLA). It may have problems if the array is too large. So if you have large images you could do:

unsigned (*arr)[m] = malloc(sizeof(unsigned[n][m]));

and later

free(arr);