CODEWITHSUNDEEP
imagecolorsimagemagickrmagickcolorize
CafeHey
CafeHey

Reputation: 5800

Using rmagick to colorize an image like in photoshop

So I have this base image:

enter image description here

And in photoshop I do a basic layer color overlay, with the rgb colors:

r: 244, g: 93, b: 0

This gives me the amazingly vibrant:

enter image description here

What I'm trying to do is colorize the same image in rmagick, so if I do the following colorize:

  img = Magick::Image.read('brush.png').first
  img = img.colorize(100, 100, 100, Magick::Pixel.new(244, 93, 0, 1))
  img.format = 'png'
  img.to_blob

It gives me this really washed out orange image:

enter image description here

My questions is, how do I colorize this image with those rgb params in imagemagick / rmagick, to get the same vibrant color that I got in photoshop.

Thanks.

Upvotes: 4

Views: 1630

Answers (2)

TechSpud
TechSpud

Reputation: 3518

Mark Setchell's command line works for me (Windows), with slight modifications...

convert greyscale.png +clone -fill "rgb(244,93,0)" -colorize 100% -compose colorize -composite colour.png

Found this link on recolouring with rmagick... ftp://belagro.com/Redmine/ruby/lib/ruby/gems/1.8/gems/rmagick-2.12.0/doc/colorize.rb.html

Based on the code in the above link, with the greyscale conversion removed, does the example below work (I don't have ruby)?

# load the greyscale image
img = Magick::Image.read('greyscale.png').first
# Colorize with a 100% blend of the orange color
colorized = img.colorize(1, 1, 1, '#A50026')
# save the colour image
colorized.write('colour.png')

Used a colour picker to get the hex of your orange colour - rgb(244,93,0) = #A50026

Upvotes: 2

Mark Setchell
Mark Setchell

Reputation: 207345

At the commandline, I think you want something like this:

convert brush.png \( +clone -fill "rgb(244,93,0)" -colorize 100% \) -compose colorize  -composite out.png

enter image description here

So, with the +clone I am creating another layer the same size as your image and entirely filling it 100% with your orange colour and then composing it over your image with the -composite to blend the opacity and colour.

I really don't speak Ruby, but I think it will be along these lines:

#!/usr/bin/ruby

require 'RMagick'
include Magick
infile=ARGV[0]
img=Magick::Image.read(infile).first
w=img.columns
h=img.rows
ovl=Image.new(w,h){self.background_color=Magick::Pixel.new(244*256,93*256,0)}
img.composite!(ovl,0,0,Magick::ColorizeCompositeOp)
img.write('result.png')

Upvotes: 3

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