A Computational Introduction to Digital Image Processing, 2nd Edition

428 A Computational Introduction to Digital Image Processing, Second Edition

Python

# Build the dictionary.

dictionary = [chr(i) for i in range(65,91)]

buffer = dictionary[code.pop(0)]

result = buffer

for n in code:

if

n <

len(dictionary):

entry = dictionary[n]

elif n == len(dictionary):

entry = buffer + buffer[0]

else:

raise

ValueError(’Bad

compressed code: %s’ % n)

result += entry

# Add buffer+entry[0] to the dictionary.

print buffer+entry[0],len(dictionary)

dictionary += [buffer + entry[0]]

buffer = entry

return result

def imLZW(im):

"""Compress an uppercase string to a list of output code values."""

data = [format(i,’02x’) for i in im.flatten().tolist()]

# Build ...