def decode_prediction(data, w, h, bytes_per_pixel):
if bytes_per_pixel == 1:
arr = be_array_from_bytes("B", data)
arr = _delta_decode(arr, 2**8, w, h)
elif bytes_per_pixel == 2:
arr = be_array_from_bytes("H", data)
arr = _delta_decode(arr, 2**16, w, h)
elif bytes_per_pixel == 4:
# 32bit channels are also encoded using delta encoding,
# but it make no sense to apply delta compression to bytes.
# It is possible to apply delta compression to 2-byte or 4-byte
# words, but it seems it is not the best way either.
# In PSD, each 4-byte item is split into 4 bytes and these
# bytes are packed together: "123412341234" becomes "111222333444";
# delta compression is applied to the packed data.
#
# So we have to (a) decompress data from the delta compression
# and (b) recombine data back to 4-byte values.
arr = array.array(str("B"), data)
arr = _delta_decode(arr, 2**8, w * 4, h)
arr = _restore_byte_order(arr, w, h)
arr = array.array(str("f"), arr)
else:
return None
return arr.tostring()
def decode_prediction(data, w, h, bytes_per_pixel):
if bytes_per_pixel == 1:
arr = be_array_from_bytes("B", data)
arr = _delta_decode(arr, 2**8, w, h)
elif bytes_per_pixel == 2:
arr = be_array_from_bytes("H", data)
arr = _delta_decode(arr, 2**16, w, h)
elif bytes_per_pixel == 4:
# 32bit channels are also encoded using delta encoding,
# but it make no sense to apply delta compression to bytes.
# It is possible to apply delta compression to 2-byte or 4-byte
# words, but it seems it is not the best way either.
# In PSD, each 4-byte item is split into 4 bytes and these
# bytes are packed together: "123412341234" becomes "111222333444";
# delta compression is applied to the packed data.
#
# So we have to (a) decompress data from the delta compression
# and (b) recombine data back to 4-byte values.
arr = array.array(str("B"), data)
arr = _delta_decode(arr, 2**8, w*4, h)
arr = _restore_byte_order(arr, w, h)
arr = array.array(str("f"), arr)
else:
return None
return arr.tostring()
def decode_prediction(data, w, h, depth):
if depth == 8:
arr = be_array_from_bytes('B', data)
arr = _delta_decode(arr, 0x100, w, h)
elif depth == 16:
arr = be_array_from_bytes('H', data)
arr = _delta_decode(arr, 0x10000, w, h)
elif depth == 32:
arr = array.array('B', data)
arr = _delta_decode(arr, 0x100, w * 4, h)
arr = _restore_byte_order(arr, w, h)
else:
raise ValueError('Invalid pixel size %d' % (depth))
return getattr(arr, 'tobytes', getattr(arr, 'tostring'))()
def _decode_layer_groups_enabled_id(data):
return be_array_from_bytes("B", data)
def _decode_layer_selection(data):
return be_array_from_bytes("I", data[2:])
def _decode_layer_group_info(data):
return be_array_from_bytes("H", data)
def _from_32bit_raw(data, size):
pixels = be_array_from_bytes("f", data)
im = Image.new("F", size)
im.putdata(pixels, 255, 0)
return im
def _decode_layer_group_info(data):
return be_array_from_bytes("H", data)
def _decode_layer_groups_enabled_id(data):
return be_array_from_bytes("B", data)
def _decode_layer_selection(data):
return be_array_from_bytes("I", data[2:])
def _from_32bit_raw(data, size):
pixels = be_array_from_bytes("f", data)
return pixels
def _from_32bit_raw(data, size):
pixels = be_array_from_bytes("f", data)
im = Image.new("F", size)
im.putdata(pixels, 255, 0)
return im