Recipe: Processing each file in a directory with a specific extension

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Recipe: Processing each file in a directory with a specific extension

Problem

I wanted to import some images of kanji characters, but ones I got off the web had white background (with exception of color words, which had the corresponding color bg). So I wanted to mass convert them to be transparent.

Solution

I ran the following code:
| slash dir image transparent black dirName | "read all gif images, make all colors, except black, transparent, open as a SketchMorph - like from FileList menu" slash _ FileDirectory slash. black _ Color r:0 g:0 b: 0. dirName _ (FileDirectory default pathName), slash, 'kanji', slash, 'matrix_kanji', slash.dir _ FileDirectory on: dirName. dir fileNames withIndexDo: [:fname :fid | (fname asLowercase endsWith: '.gif') ifTrue: [image _ GIFReadWriter formFromFileNamed: dirName, fname. transparent _ (image colors select: [:c | c isTransparent]) first. image colors withIndexDo: [:c :i | (c isTransparent not and: [(c = black) not]) ifTrue: [image colors at: i put: transparent]]. World addMorph: (image _ SketchMorph new form: image). image position: (fid*10)@(fid*10)]].

Source

Squeak mailing list - Bolot Kerimbaev -
Subject: [GOODIE] selecting multiple morphs, kanji fun
Date: Wed, 17 Nov 1999