切片的tiff图像通过python魔杖变得更大

Question

I have a .tif file that has 10 pages. I want to create a sub-image containing only pages 2-7, but the produced file is much bigger than the orginal. It should be smaller. What would you suggest? Here is my code:

from wand.image import Image

with Image(filename='test.tif') as original:
    with Image() as sub_image:
        sub_image.sequence.extend(original.sequence[2:7])
        sub_image.save(filename='sub.tif')

Original: 3mb

Sub: 50mb (!)

EDIT: Here a sample source file : tif file

Answer 1

There's a lot at play in the TIFF file. Try the following in the command line.

convert 'test.tif[2-7]' \
        -define 'tiff:rows-per-strip=3504' \
        -colorspace YCBCR \
        -alpha remove \
        -auto-level \
        -compress JPEG \
        -endian LSB \
        -depth 8 \
        output.tif

All options above match the original file except rows-per-strip . The original document has rows-per-strip of 3507; which is not a multiple of 8 (don't know what impact that would have).

The majority of the options are supported by wand , and should be implemented / respected in your calling script.

For -define 'tiff:rows-per-strip=3504' , see this answer .