|
|
|
@ -23,16 +23,16 @@ import struct
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
def getBox(data, byteStart, noBytes):
|
|
|
|
|
boxLengthValue = struct.unpack(">I", data[byteStart:byteStart+4])[0]
|
|
|
|
|
boxType = data[byteStart+4:byteStart+8]
|
|
|
|
|
boxLengthValue = struct.unpack(">I", data[byteStart : byteStart + 4])[0]
|
|
|
|
|
boxType = data[byteStart + 4 : byteStart + 8]
|
|
|
|
|
contentsStartOffset = 8
|
|
|
|
|
if boxLengthValue == 1:
|
|
|
|
|
boxLengthValue = struct.unpack(">Q", data[byteStart+8:byteStart+16])[0]
|
|
|
|
|
boxLengthValue = struct.unpack(">Q", data[byteStart + 8 : byteStart + 16])[0]
|
|
|
|
|
contentsStartOffset = 16
|
|
|
|
|
if boxLengthValue == 0:
|
|
|
|
|
boxLengthValue = noBytes-byteStart
|
|
|
|
|
boxLengthValue = noBytes - byteStart
|
|
|
|
|
byteEnd = byteStart + boxLengthValue
|
|
|
|
|
boxContents = data[byteStart+contentsStartOffset:byteEnd]
|
|
|
|
|
boxContents = data[byteStart + contentsStartOffset : byteEnd]
|
|
|
|
|
return (boxLengthValue, boxType, byteEnd, boxContents)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
@ -52,14 +52,15 @@ def parse_colr(data):
|
|
|
|
|
elif enumCS == 17:
|
|
|
|
|
return "L"
|
|
|
|
|
else:
|
|
|
|
|
raise Exception("only sRGB and greyscale color space is supported, "
|
|
|
|
|
"got %d" % enumCS)
|
|
|
|
|
raise Exception(
|
|
|
|
|
"only sRGB and greyscale color space is supported, " "got %d" % enumCS
|
|
|
|
|
)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
def parse_resc(data):
|
|
|
|
|
hnum, hden, vnum, vden, hexp, vexp = struct.unpack(">HHHHBB", data)
|
|
|
|
|
hdpi = ((hnum/hden) * (10**hexp) * 100)/2.54
|
|
|
|
|
vdpi = ((vnum/vden) * (10**vexp) * 100)/2.54
|
|
|
|
|
hdpi = ((hnum / hden) * (10 ** hexp) * 100) / 2.54
|
|
|
|
|
vdpi = ((vnum / vden) * (10 ** vexp) * 100) / 2.54
|
|
|
|
|
return hdpi, vdpi
|
|
|
|
|
|
|
|
|
|
|
|
|
|
@ -69,9 +70,8 @@ def parse_res(data):
|
|
|
|
|
byteStart = 0
|
|
|
|
|
boxLengthValue = 1 # dummy value for while loop condition
|
|
|
|
|
while byteStart < noBytes and boxLengthValue != 0:
|
|
|
|
|
boxLengthValue, boxType, byteEnd, boxContents = \
|
|
|
|
|
getBox(data, byteStart, noBytes)
|
|
|
|
|
if boxType == b'resc':
|
|
|
|
|
boxLengthValue, boxType, byteEnd, boxContents = getBox(data, byteStart, noBytes)
|
|
|
|
|
if boxType == b"resc":
|
|
|
|
|
hdpi, vdpi = parse_resc(boxContents)
|
|
|
|
|
break
|
|
|
|
|
return hdpi, vdpi
|
|
|
|
@ -83,13 +83,12 @@ def parse_jp2h(data):
|
|
|
|
|
byteStart = 0
|
|
|
|
|
boxLengthValue = 1 # dummy value for while loop condition
|
|
|
|
|
while byteStart < noBytes and boxLengthValue != 0:
|
|
|
|
|
boxLengthValue, boxType, byteEnd, boxContents = \
|
|
|
|
|
getBox(data, byteStart, noBytes)
|
|
|
|
|
if boxType == b'ihdr':
|
|
|
|
|
boxLengthValue, boxType, byteEnd, boxContents = getBox(data, byteStart, noBytes)
|
|
|
|
|
if boxType == b"ihdr":
|
|
|
|
|
width, height = parse_ihdr(boxContents)
|
|
|
|
|
elif boxType == b'colr':
|
|
|
|
|
elif boxType == b"colr":
|
|
|
|
|
colorspace = parse_colr(boxContents)
|
|
|
|
|
elif boxType == b'res ':
|
|
|
|
|
elif boxType == b"res ":
|
|
|
|
|
hdpi, vdpi = parse_res(boxContents)
|
|
|
|
|
byteStart = byteEnd
|
|
|
|
|
return (width, height, colorspace, hdpi, vdpi)
|
|
|
|
@ -101,9 +100,8 @@ def parsejp2(data):
|
|
|
|
|
boxLengthValue = 1 # dummy value for while loop condition
|
|
|
|
|
width, height, colorspace, hdpi, vdpi = None, None, None, None, None
|
|
|
|
|
while byteStart < noBytes and boxLengthValue != 0:
|
|
|
|
|
boxLengthValue, boxType, byteEnd, boxContents = \
|
|
|
|
|
getBox(data, byteStart, noBytes)
|
|
|
|
|
if boxType == b'jp2h':
|
|
|
|
|
boxLengthValue, boxType, byteEnd, boxContents = getBox(data, byteStart, noBytes)
|
|
|
|
|
if boxType == b"jp2h":
|
|
|
|
|
width, height, colorspace, hdpi, vdpi = parse_jp2h(boxContents)
|
|
|
|
|
break
|
|
|
|
|
byteStart = byteEnd
|
|
|
|
@ -119,6 +117,7 @@ def parsejp2(data):
|
|
|
|
|
|
|
|
|
|
if __name__ == "__main__":
|
|
|
|
|
import sys
|
|
|
|
|
|
|
|
|
|
width, height, colorspace = parsejp2(open(sys.argv[1]).read())
|
|
|
|
|
sys.stdout.write("width = %d" % width)
|
|
|
|
|
sys.stdout.write("height = %d" % height)
|
|
|
|
|