A quick question about multiply

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
thanhhuyen8653
Posts: 1
Joined: 2018-07-10T18:20:42-07:00
Authentication code: 1152

A quick question about multiply

Post by thanhhuyen8653 » 2018-07-10T18:26:30-07:00

Sorry if this is a simple question, but I can't find info online.

I have substracted two images and would like scale the resulting diff image by some constant to make differences more noticeable. I'd imagine ImageMagick is able to do this, but I can't find the right commands for this. Can anyone point me to the right place, documentation?

User avatar
fmw42
Posts: 23384
Joined: 2007-07-02T17:14:51-07:00
Authentication code: 1152
Location: Sunnyvale, California, USA

Re: A quick question about multiply

Post by fmw42 » 2018-07-10T18:35:47-07:00

You could just use -auto-level. It would automatically stretch the dynamic range to full black and full white.

Alternately, you can use -evaluate multiply X, where X is some multiplier factor.

See
http://www.imagemagick.org/script/comma ... auto-level
http://www.imagemagick.org/script/comma ... p#evaluate

snibgo
Posts: 10357
Joined: 2010-01-23T23:01:33-07:00
Authentication code: 1151
Location: England, UK

Re: A quick question about multiply

Post by snibgo » 2018-07-11T02:49:29-07:00

The identical question was asked, and answered, four years ago.

The spammer is now banned.
snibgo's IM pages: im.snibgo.com

Post Reply