Create gradient and compose with image in one command

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?".
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stefda@gmail.com
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Create gradient and compose with image in one command

Post by stefda@gmail.com » 2018-12-25T22:28:49-07:00

I can't figure out if it is possible to create a new image with gradient and compose it with an existing image in one command. Please help.

Command to generate the gradient:

Code: Select all

convert -size 1200x747 gradient: gradient.jpg
Command to compose the gradient with an existing `input.jpg`:

Code: Select all

convert input.jpg gradient.png -compose linear_burn -composite output.jpg
Ideally, I'd like to get output.jpg in "one step", using the convert command, without having to generate and store the gradient.jpg image beforehand.

stefda@gmail.com
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Re: Create gradient and compose with image in one command

Post by stefda@gmail.com » 2018-12-26T01:29:26-07:00

A few more searches and I finally understand the anatomy of the command line! What I'm after above can be achieved with this simple command:

Code: Select all

convert input.jpg -size 1200x747 gradient: -compose linear_burn -composite output.jpg
🤦‍♂️

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fmw42
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Re: Create gradient and compose with image in one command

Post by fmw42 » 2018-12-26T10:37:49-07:00

why linear burn and not just -compose over?

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