// iterate over infile's scanlines
    for (int i = 0; i < abs(inputHeight); i++)
    {
        // iterate over pixels in scanline
        for (int j = 0; j < inputWidth; j++)
        {
            // temporary storage
            RGBTRIPLE triple;

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

            // duplicate each pixel n times horizontally
            for (int p = 0; p < n; p++)
            {
                // write RGB triple to outfile
                fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
            }
        }
        // temporary storage
        RGBTRIPLE triple2;

        // read RGB triple from row of outfile
        fread(&triple2, sizeof(RGBTRIPLE), bi.biWidth, outptr);

        // duplicate each row n times vertically
        for (int q = 0; q < n; q++)
        {
            fwrite(&triple2, sizeof(RGBTRIPLE), bi.biWidth, outptr);
        }