Function _jpegxy

IPython/core/display.py:808–825

read the (width, height) from a JPEG header

(data)

def _jpegxy(data):
    """read the (width, height) from a JPEG header"""
    # adapted from http://www.64lines.com/jpeg-width-height

    idx = 4
    while True:
        block_size = struct.unpack('>H', data[idx:idx+2])[0]
        idx = idx + block_size
        if data[idx:idx+2] == b'\xFF\xC0':
            # found Start of Frame
            iSOF = idx
            break
        else:
            # read another block
            idx += 2

    h, w = struct.unpack('>HH', data[iSOF+5:iSOF+9])
    return w, h


def _gifxy(data):