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Kelbie/blocktoimg.py

Forked from laanwj/blocktoimg.py
Created July 29, 2018 03:25
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simple tools to write (block) data to png files
Raw
blocktoimg.py
#!/usr/bin/env python3
# Distributed under the MIT software license
import binascii, struct, sys
from PIL import Image
def div_roundup(x,y):
return (x+y-1)//y
f = open(sys.argv[1], 'r')
outfilename = sys.argv[2]
blockdata = binascii.a2b_hex(f.read().strip())
metaheader = struct.pack('>II', len(blockdata), binascii.crc32(blockdata))
data = metaheader + blockdata
pixels=div_roundup(len(data), 4)
width=512 # could be made adaptive...
height=div_roundup(pixels, width)
print('exporting %d×%d to %s' % (width,height,outfilename))
padding_len = width*height*4 - len(data)
data += b'\x00' * padding_len
img = Image.frombytes("RGBA", (width, height), data)
img.save(outfilename)
Raw
imgtoblock.py
#!/usr/bin/env python3
# Distributed under the MIT software license
import binascii, struct, sys
from PIL import Image
img = Image.open(sys.argv[1])
outfilename = sys.argv[2]
assert(img.format == 'PNG' and img.mode == 'RGBA')
imgdata = img.tobytes()
metaheader = imgdata[0:8]
(blocksize,crc) = struct.unpack('>II', metaheader)
print('size {:d}×{:d}'.format(img.width, img.height))
print('metaheader:')
print(' size : {:d}'.format(blocksize))
print(' CRC32 : {:x}'.format(crc))
assert(8+blocksize <= len(imgdata))
blockdata = imgdata[8:8+blocksize]
assert(binascii.crc32(blockdata) == crc)
with open(outfilename, 'w') as f:
f.write(binascii.b2a_hex(blockdata).decode())
f.write('\n')
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