bitmap processing in C

[cyrak]

I'm trying to do some processing in .bmp files and I need to use C, I've used it quite a bit except for image processing...an d I'm trying to read the header block and pretty much from there just travel through the pixels and compare it with other file.

I haven't really worked on images before...so any pointers would be appreciated
this is what I'm trying to do to open the file..but I don't seem to be able to parse through the Header....any ideas, or other paths that I can take ?

FILE *fp;
fp = fopen("kitty.bm p","r");
unsigned char Header[0x435], image[256][256];
fread(Header,1, 0x435,fp); // copy image header to Header array
fseek(fp,0x436, SEEK_SET); // Move file pointer to start of image data
fread(image,1,2 56*256,fp); // read image data and copy to ImageIn1[][] array

thanks in advance

[Savage]

This would be the pseudo code for loadin in the bitmap

If open Bitmap file
Read two bytes (type) and if different than 0x4D42 stop
Ignore eight bytes
Read four bytes (start of image data)
Ignore four bytes
Read four bytes (width of bitmap)
Read four bytes (height of bitmap)
Ignore two bytes
Read two bytes (bit count of bitmap) and if different than 24 stop//24bit BMP only
Read four bytes (compression of bitmap) and if different than BI_RGB stop//No compression
Move to start of image data
Allocate memory for image data (3(one byte for red, other for 
green other for blue) * ImageWidth * ImageHeight)
Read (3 * ImageWidth * ImageHeight) bytes from file to buffer
Swap the red and blue components of buffer
If ImageHeight is negative
Flip the buffer lines
End if
Close file

Do you see now,where have you gone wrong?

[weaknessforcats]

Are you using Windows? These bitmap funcitons are already written and are part of Win32.