Replace solid color with oriented gradient

[Tyvain]

Hello all,

I am trying to make a script to replace a color from an image with a gradient oriented one. The goal is make an animated image with the gradient color turning.
I try diffrent commands but was unable to do it. My main problem is that this command "convert source.jpg -size 1000x496 gradient:yellow-green -opaque "#0973A5" res2.jpg" create a square gradient, and not a gradient replacing the given color.

here is my source image:
here is what i would like to have in result (the angle of the gradient can change):

i someone can help please.

Sorry if my english is not very good.

Thank you.

[snibgo]

I would break the problem down into stages. One stage is to replace the solid blue with a gradient blue. You can create the gradient blue (Windows script), at any angle you want:

Code: Select all

convert -size 140x140 gradient:rgb(0,0,64)-rgb(200,200,255) -rotate 45 +repage grad1.png

I will make the solid blue transparent, and overlay the result over the gradient. But the background is already transparent, so I will first make that red.

Code: Select all

convert ring.png ( +clone -fill Red -colorize 100 ) +swap -composite rNT.png

set COL1=rgb(0,147,238)

convert rNT.png -transparent %COL1% r2.png

convert grad1.png r2.png -gravity center -composite -crop 96x96+0+0 +repage r.png

[fmw42]

removed -- misread the issue

[Tyvain]

I would break the problem down into stages. One stage is to replace the solid blue with a gradient blue. You can create the gradient blue (Windows script), at any angle you want:

Code: Select all

convert -size 140x140 gradient:rgb(0,0,64)-rgb(200,200,255) -rotate 45 +repage grad1.png

I will make the solid blue transparent, and overlay the result over the gradient. But the background is already transparent, so I will first make that red.

Code: Select all

convert ring.png ( +clone -fill Red -colorize 100 ) +swap -composite rNT.png

set COL1=rgb(0,147,238)

convert rNT.png -transparent %COL1% r2.png

convert grad1.png r2.png -gravity center -composite -crop 96x96+0+0 +repage r.png

wow thank you very much!!
this is working great and do exactly what i need!!

[king111]

I would break the problem down into stages. One stage is to replace the solid blue with a gradient blue. You can create the gradient blue (Windows script), at any angle you want:

Code: Select all

convert -size 140x140 gradient:rgb(0,0,64)-rgb(200,200,255) -rotate 45 +repage grad1.png

I will make the solid blue transparent, and overlay the result over the gradient. But the background is already transparent, so I will first make that red.

Code: Select all

convert ring.png ( +clone -fill Red -colorize 100 ) +swap -composite rNT.png

set COL1=rgb(0,147,238)

convert rNT.png -transparent %COL1% r2.png

convert grad1.png r2.png -gravity center -composite -crop 96x96+0+0 +repage r.png

Can you tell all the steps for PHP ?

[snibgo]

Put each "convert" command in an exec().