PS4 Resize makes random colors

Question

So, I'm in the midst of PS4 resize, and while I know I'm still figuring out an array of different things, when i currently perform the resize (even if I "resize" it to the same size) it seems to be picking and assigning RANDOM colors to the output file.

This is what it does to "smiley.bmp". I just don't get where it would be pulling these colors FROM.

// iterate over infile's scanlines
for (int i = 0, biHeight = abs(bi.biHeight); i < biHeight; i++)
{
    // iterate over multipled rows in new file
    for (int j = (i * n); j < ((i * n) + n); j++)
    {   
        //GO BACK TO BEGINNING OF SCANLINE     
        fseek(inptr, (i * bi.biWidth), SEEK_SET);

        // iterate over pixels in scanline
        for (int p = 0; p < bi.biWidth; p++)
        {
            // temporary storage
            RGBTRIPLE triple;

            // read RGB triple from infile
            fread(&triple, sizeof(RGBTRIPLE), 1, inptr);

            // write RGB triple to outfile
            for (int w = (p * n); w < ((p * n) + n); w++)
            {
                fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
            }
        }

        // skip over padding, if any
        fseek(inptr, padding, SEEK_CUR);

        // then add it back (to demonstrate how)
        for (int k = 0; k < padding; k++)
        {
            fputc(0x00, outptr);
        }
    }

Answer 1

There are several problems in the code, but the biggest is this:

        //GO BACK TO BEGINNING OF SCANLINE     
    fseek(inptr, (i * bi.biWidth), SEEK_SET);

The third parameter is the starting point and the second parameter is the offset. SEEK_SET is the beginning of the file, so starting at the beginning of the file, you are saying to move to i * bi.biWidth. Let's say that i is 0. Then the offset is 0. That means 'move to the start of the file'. So, the code will start processing the header data as image data. You forgot to skip forward past the headers.

Interestingly, if you comment this line out, the file should generate a correct output file for scaling of 1. It did when I put your code into mine to run it.

You need to figure out how to correctly reposition at the start of each line.

Another problem: It appears that you are using the input padding for the output padding. The output padding will change as the scaling changes and must be calculated.

There are other issues, but this will get you going.

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