fast identify for actual bit depth

[fmw42]

The string formats "%z" and "%[depth]" only show 8 vs 16, etc (depending upon quantumrange). If one has a binary image the depth in the verbose info shows 8/1-bit.

It would be nice to get the actual bit-depth of 1 in this case.

Right now I can do it by extracting that from the IM verbose information.

# create depth 1 image

convert rose: -threshold 50% rose_t50.png
identify -verbose rose_t50.png
...
Depth: 8/1-bit

In unix, this could get extracted by

depth=`convert rose_t50.png -verbose info: | sed -n 's/^ Depth:[^0-9]*\(.*\)-bit$/\1/p' | tr "/" " " | cut -d\ -f2`
echo "$depth"
1

depth=`convert rose: -verbose info: | sed -n 's/^ Depth:[^0-9]*\(.*\)-bit$/\1/p' | tr "/" " " | cut -d\ -f2`
echo "$depth"
8


It might be nice to have a new string format

convert image -format "%[bit-depth] info:

or if one prefers

convert image -format "%[bitdepth] info:

That gets the actual bit depth such a 1

[dlemstra]

I prefer bit-depth, it will be available in the next release of ImageMagick.

Code: Select all

C:\Test>identify -format "%[bit-depth]" rose:
8
C:\Test>identify -format "%[bit-depth]" rose_t50.png
1

[fmw42]

Thanks.

Fred