private int gray(final int argb) {
        final int r = argb >> 16 & 0xff;
        final int g = argb >> 8 & 0xff;
        final int b = argb & 0xff;
        return (int) (0.299 * r + 0.587 * g + 0.114 * b + 0.5);
    }
Reads files in the BigTIFF samples folder and compares the BigTIFF files against the standard "classic" tiff image.
src/test/java/org/apache/commons/imaging/formats/tiff/TiffJpegTest.java