Legacy ImageMagick Discussions Archive

How do you write the histogram of an image to a text file?

Taking the examples in the docs...
shows the histogram, which is 6 different colours on 6 lines, however, using creates a 1026 line file, containing a line for each pixel in the 32x32 image.

Can somebody enlighten me please?

Thanks

Matt

convert tree.gif -format %c histogram:info:- >2 file.txt

Thanks!

I had to remove the "2" though - was that a typo?

Not a typo. The >2 was needed on my Mac OSX (unix) environment and does not work without the 2. Are you on Window? or some other Linux?

Hmm. I'm on Windows. Interesting.

actually I believe more properly on unix it should be

convert tree.gif -format %c histogram:info:- 2>&1 file.txt

I tried that on my WIn XP system and the output does get sent to standard output whereas on the Mac (and Linux?) it would appear that it gets sent to standard error.

Pete

fmw42 wrote:actually I believe more properly on unix it should be

convert tree.gif -format %c histogram:info:- 2>&1 file.txt

Trying this on Windows gave me a 90000 line pixel enumeration file.

I think I'll stick with what I have for the time being.

Thanks guys.

Or even better, write it directly to the file, rather than tto stdout/stderr (the meaning of ther '-')