Histogram Output Oddness

Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
Post Reply
Posts: 68
Joined: 2007-06-12T21:03:18+00:00

Histogram Output Oddness

Post by blue-j »

Hi everyone! I hope you are well during this crazy time. I'm having an oddity with histogram output:

Code: Select all

convert in.jpg  -alpha off -depth 8 -flatten -separate -append -strip -define histogram:unique-colors=false histogram:histo.gif
is outputting a fine global histogram, except it has a huge spike in the bin of pure white all the way to the top. It seems this occurs no matter what image I use as input! (I would provide a sample but believe it is irrelevant and will happen for you, too! Please tell me if I'm wrong of course.) I just tried a simple JPG with no odd features, no alphas, no paths, nothing odd.

My build, installed with Homebrew on macOS 10.15.7:

ImageMagick 7.0.10-34 Q16 x86_64 2020-10-09
Features: Cipher DPC HDRI Modules OpenMP(4.5)
Delegates (built-in): bzlib freetype gslib heic jng jp2 jpeg lcms lqr ltdl lzma openexr png ps tiff webp xml zlib
Post Reply