How to build this effect in Image Magick?

[pimboli]

Hi,

can someone please tell me how can I create this effect in imageMagick?

2 images, one as overlay with a gradient in the middle over the first image.



Thank you in advance.

Pim.

[fmw42]

Unix syntax:

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convert image1 image2 \( -clone 1 -channel rgba -alpha transparent -sparse-color barycentric '0,0 white  %w,0 black' \) -compose over -composite result

See
https://imagemagick.org/Usage/canvas/#t ... _gradients
https://imagemagick.org/Usage/compose/#compose

________

Please, always provide your IM version and platform when asking questions, since syntax may differ.

Also provide your exact command line and your images, if possible.

See the top-most post in this forum "IMPORTANT: Please Read This FIRST Before Posting" at http://www.imagemagick.org/discourse-se ... f=1&t=9620

If using Imagemagick 7, then see http://imagemagick.org/script/porting.php#cli


For novices, see

http://www.imagemagick.org/discourse-se ... f=1&t=9620
http://www.imagemagick.org/script/comma ... essing.php
http://www.imagemagick.org/Usage/reference.html
http://www.imagemagick.org/Usage/
https://github.com/ImageMagick/usage-markdown

[pimboli]

Thank you @fmw42 for your reply and your explications, wow I would like to have your IM skills

I am on IM7 on OSx:
convert --version
Version: ImageMagick 7.0.8-11 Q16 x86_64 2018-09-08 https://www.imagemagick.org

The command that you gave me does not work, I suppose it's related to IM7?

I tried with:

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convert 1.jpg 2.jpg \( -clone 1 -channel rgba -alpha transparent -sparse-color barycentric '0,0 white  %w,0 black' \) -compose over -composite result.jpg

In the result.jpg I only see 2.jpg ass output.

[GeeMack]

I am on IM7 on OSx:
convert --version
Version: ImageMagick 7.0.8-11 Q16 x86_64 2018-09-08 https://www.imagemagick.org

The command that you gave me does not work, I suppose it's related to IM7?

If you're using IM7 you should be using the command "magick" instead of "convert".

This command is nearly the same as fmw42's, and it works for me using "convert" with IM 6.8.9-9 in a bash shell. Also, by eliminating the backslashes "\" it works with IM 6.9.10-11 in Windows, and by using "magick" with IM 7.0.8-12 in Windows...

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magick in1.jpg in2.jpg ( -clone 0 -sparse-color barycentric "0,0 black %[w],0 white" ) -composite out.jpg

If it doesn't work, maybe you can upload your input images to a public server so we can test them to find the source of your problem.

[fmw42]

Yes, I believe Windows requires double quotes and as Geemack said remove the \s from my command and for IM 7 use magick not convert.

[pimboli]

Thanks guys I really appreciate your help!

I have no success..

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magick 1.jpg 2.jpg \( -clone 1 -channel rgba -alpha transparent -sparse-color barycentric '0,0 white  %w,0 black' \) -compose over -composite result.jpg

still gets me as result the 2.jpg

I even tried with magick instead of convert due to the facts that I am on IM7.

I think I need to \ the "(" on mac (its a bash shell).
If I run command without / I get an error:

bash-3.2$ magick 1.jpg 2.jpg ( -clone 1 -channel rgba -alpha transparent -sparse-color barycentric '0,0 white %w,0 black' ) -compose over -composite result.jpg
bash: syntax error near unexpected token `('

Here are the input images and the result.jpg:

https://imgur.com/a/8Y2mIsU

As you can see result.jpg = 2.jpg but not the required effect.

[pimboli]

I tried now on a linux vps with IM 6,
and there it seems to work with convert instead of magick.

https://imgur.com/a/8Y2mIsU => look at result_linux.jpg.

In worst-case I could let run the script later under linux.

Could please tell me if you know how I could make the beginning and the end of the image "un-transparent" and only the middle part transparent gradient.

How I would like to have the image:


my result under linux:


Thanks!

[fmw42]

Could please tell me if you know how I could make the beginning and the end of the image "un-transparent" and only the middle part transparent gradient.

How much of the ends and middle? 1/3, 1/3, 1/3? or some other portions?

[snibgo]

See also this recent thread: https://www.imagemagick.org/discourse-s ... =1&t=34789

[pimboli]

Could please tell me if you know how I could make the beginning and the end of the image "un-transparent" and only the middle part transparent gradient.

How much of the ends and middle? 1/3, 1/3, 1/3? or some other portions?

Yes 1/3, 1/3 , 1/3 would be good I think so.
If you could give me the command I can adapt it in case I would like to change the proportions.

Many thanks!

[GeeMack]

Yes 1/3, 1/3 , 1/3 would be good I think so.
If you could give me the command I can adapt it in case I would like to change the proportions.

In the example commands above there's a section inside parentheses. That's where you're creating the mask for the gradient overlay. You can use FX expressions in that "-sparse-color" operation to make the black and white start and end wherever you like. Here's a way to make that mask for a 1/3 solid first image, 1/3 fade to second image, and end with a 1/3 solid second image...

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... \( -clone 0 -sparse-color barycentric "%[fx:w*0.333],0 black %[fx:w*0.667],0 white" \) ...

Those FX expressions are calculating some amount of the width of the image, "w*0.333". Adjust them to suit your need. Learn more about using FX expressions at THIS link.