init

img-better.js

+// 需要 Image Magick 和 pngquant
+
+var chp = require('child_process')
+var fs = require('fs')
+var path = require('path')
+var os = require('os')
+
+function betterImg(img) {
+    
+    var tmpDir = os.tmpdir()
+    var fname = new Date().getTime().toString() + '.jpg'
+    fname = path.join(tmpDir, fname)
+    fs.writeFileSync(fname, img)
+    fnamePng = fname.slice(0, -4) + '-conv.png'
+    fnameFs8 = fnamePng.slice(0, -4) + '-fs8.png'
+    chp.spawnSync('magick', ['convert', fname, fnamePng])
+    chp.spawnSync('pngquant', ['8', fnamePng])
+    if(fs.existsSync(fnameFs8)) {
+        img = fs.readFileSync(fnameFs8)
+        safeUnlink(fnameFs8)
+    }
+    safeUnlink(fnamePng)
+    safeUnlink(fname)
+    return img
+}
+
+module.exports = betterImg
+
+function safeUnlink(f){
+    
+    try {fs.unlinkSync(f)}
+    catch(ex) {}
+}
+
+function main() {
+
+    var dir = process.argv[2]
+    var qualify = process.argv[3] || '8'
+    var pics = fs.readdirSync(dir).filter(
+        x => x.endsWith('.jpg') || 
+             x.endsWith('.png') || 
+             x.endsWith('.gif')
+    )
+
+    for(var f of pics){
+        
+        f = path.join(dir, f)
+        console.log(f)
+        var img = fs.readFileSync(f)
+        img = betterImg(img)
+        fs.writeFileSync(f, img)
+    }
+
+}
+
+if(module == require.main) main()
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