Arithmetic compare to find darkest pixels from 2 images?

[form]

Hi.
I try to do an arithmetic comparisation of two images, to write the darkest pixel of every image to an output image.
(like the function "arithmetic/darkest" in PaintShop Pro).

Is that possible with ImageMagick?
Please help me out.

[form]

I figured it out myself:

Code: Select all

composite -compose darken 1.bmp 2.bmp out.bmp

[anthony]

I would be interested to know what you use this for!

Basically I breifly documented the operation in IM examples, But never knew why you want to do this.

The same goes for a number of other operations.

WARNING: some programs only restrict the draken/lighen test to just the individual channels of the two images and not the pixels overall grayscale color. Caution is advised.

[form]

I would be interested to know what you use this for!

I compare 100 snapshots of a tv-series with that, to get one picture where only the TV-Logo stays visible.
Then it can be used for a de-logo filter, which blends that logo out.

Btw, i cant find that "darken" function in your IM Examples. Under which category did you described it?

[anthony]

Darken and Lighen are listed together in IM examples
http://imagemagick.org/Usage/compose/#lighten
http://imagemagick.org/Usage/compose/#darken