Legacy ImageMagick Discussions Archive

I would like to be able to convert a logo for a website (e.g. help icon) to a different color, specified on input. I am able to gain the desired effect using the '-modulate' operator, but the outcome is determined as a rotation of color values.

Basic example: the current logo color is green, and the user decides it should be purple. The user enters purple, along with the logo. The result is a new logo which is now purple.

I have thought about using masks and transparency, and changing the original image to black and white. Is this a good route to explore, or is there an easier method?

Thankyou for your help.

convert the logo to a greyscale version. then use -tint (set grey colors) or +level-colors (set black/white gradient) to color the image to ANY color by name or value!

See IM Examples, Color Modifications

Level Adjustment by Color
http://www.imagemagick.org/Usage/color/#level-colors

Midtone Color Tinting
http://www.imagemagick.org/Usage/color/#tint

Thanks for that Anthony, I'll take a closer look at those operators.

anthony wrote:convert the logo to a greyscale version. then use -tint (set grey colors) or +level-colors (set black/white gradient) to color the image to ANY color by name or value!

See IM Examples, Color Modifications

Level Adjustment by Color
http://www.imagemagick.org/Usage/color/#level-colors

Midtone Color Tinting
http://www.imagemagick.org/Usage/color/#tint

I've had a quick go at manipulating the .gif by the above method and it seems that not enough of the 'secondary' colour are preserved. i.e I want to define the main color, not the entire icon (see the handle in the example below). Having said that, It wouldn't matter too much, but I would need to get the result a little darker - with more contrast.

Here is an example of the different methods.

The input image.



Conversion using hue offset of 10 (-modulate 100,100,10)



Conversion using the above method (grayscale then recoloring)



Just thought I'd give some feedback.. and to see if anyone has any other suggestions. I will look into the documentation more tomorrow for inspiration, but for now it's very late (UK time). Thanks again for any help.

For this image you woyld make sure the circle and the magnifying glass is black, You can then use -tint to tint the grey parts.

However I agree modulate would probably be the better method for the image in question.

NOTE 100,100,100 is NO change.