private static boolean isGifHeader(final byte[] imageHeaderBytes, final int headerSize) {
    if (headerSize < GIF_HEADER_LENGTH) {
      return false;
    }
    return ImageFormatCheckerUtils.startsWithPattern(imageHeaderBytes, GIF_HEADER_87A) ||
        ImageFormatCheckerUtils.startsWithPattern(imageHeaderBytes, GIF_HEADER_89A);
  }
private static boolean isGifHeader ( final byte [ ] imageHeaderBytes , final int headerSize ) { if ( headerSize < GIF_HEADER_LENGTH ) { return false ; } return ImageFormatCheckerUtils . startsWithPattern ( imageHeaderBytes , GIF_HEADER_87A ) || ImageFormatCheckerUtils . startsWithPattern ( imageHeaderBytes , GIF_HEADER_89A ) ; }
Checks if first headerSize bytes of imageHeaderBytes constitute a valid header for a gif image.
Details on GIF header can be found <a href="http://www.w3.org/Graphics/GIF/spec-gif89a.txt">
on page 7</a>
@param imageHeaderBytes
@param headerSize
@return true if imageHeaderBytes is a valid header for a gif image