download: https://www.dropbox.com/s/i2zohq8oa0jmcop/Transparency.jar?dl=0
java -jar Transparency.jar -i Feathers.png -c 0 0 255 -b background.jpg
Source feather
Isolated foreground:
Blended into a background image:
Mileage may vary. Best results when background is solid colors, and differentiable from foreground easily.
java Transparency -i inputFile [-c r g b] [-o outputFile] [-b bgFile1 bgFile2 ...] [-p] [-d width height] or java -jar Transparency.jar -i inputFile [-c r g b] [-o outputFile] [-b bgFile1 bgFile2 ...] [-p] [-d width height] if you have a .jar -i Path to the input file.
-c The RGB value to de-blend into transparency. Optional. Defaults to 0,0,0 (black).
-o Path to the output file. Optional. Defaults to input file + "_out".
-b List of paths to background files to blend into in order. Optional.
-p Use premultiplied argb processing. Optional.
-d Dimensions of the output. Optional. Defaults to the dimensions of the input.
-n Don't attempt to deblend image first. Instead, blend input directly with any backgrounds. Optional.
Current issues: If the input file is a file with transparency ... stuff goes wrong.