mirror of
https://github.com/danbulant/pngjs
synced 2026-05-20 04:39:01 +00:00
26 lines
717 B
JavaScript
26 lines
717 B
JavaScript
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var fs = require('fs'),
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PNG = require('pngjs').PNG;
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fs.createReadStream('in.png')
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.pipe(new PNG({
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filterType: 4
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}))
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.on('parsed', function() {
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for (var y = 0; y < this.height; y++) {
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for (var x = 0; x < this.width; x++) {
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var idx = (this.width * y + x) << 2;
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// invert color
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this.data[idx] = 255 - this.data[idx];
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this.data[idx+1] = 255 - this.data[idx+1];
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this.data[idx+2] = 255 - this.data[idx+2];
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// and reduce opacity
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this.data[idx+3] = this.data[idx+3] >> 1;
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}
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}
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this.pack().pipe(fs.createWriteStream('out.png'));
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});
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