Question

Edited: Thanks for the previous answers and help! I’ve decided to edit this question into what I need exactly, sorry for not being as specific earlier.

Basically the title is all the information, this is currently what I’m working with:

int channels = 4;
int length = width * height;
int[] data = new int[length * channels];
int[][] channelPixels = new int[4][length];

for (int c = 0; c < channels; c++) {
    for (int i = 0; i < length; i++) {
        channelPixels[c][i] = readByte();
    }
}

Unfortunately, the colors don’t seem to match up to the originals.

Is there something I’m doing wrong here?

Answer 1

This code flips rectangular buffer and changes RGBA byte order to BGRA (or vice versa) like this:

a b c d e f g h
i j k l m n o p
=>
k j i l o n m p
c b a d g f e h

Rough analog with c/java-like pseudocode:

src = array of byte with length (RawHdr.Width * RawHdr.Height * 4)
dst = array of byte with the same length

dstindex = 0

for (i = RawHdr.Height - 1; i >= 0; i--)
    {
     srcstartindex = i * RawHdr.Width * 4;
     for (j = 0; j < RawHdr.Width; j++)
         {  
           si = srcstartindex + j * 4;
           dst[dstindex] = src[si + 2];
           dst[dstindex + 1] = src[si + 1];
           dst[dstindex + 2] = src[si];
           dst[dstindex + 3] = src[si + 3];
           dstindex +=4;
         }
     }