Alpha channel turns black

[jacobtomlinson]

Thanks for this library, it's great!

One problem I've found when adding watermarks to PNGs with transparency is that the transparency turns black.

Any ideas on how to fix this?

[furagu]

Hey! Good to hear you liked the library.

Actually it should handle the transparency correctly. So, could you provide some sample files and code? I can take a look and just fix that.

[jacobtomlinson]

Yeah no problem, I'll just get you some example code.

[jacobtomlinson]

Original files

input.png smiley.png

Code

    var outStream = fs.createWriteStream('/tmp/output.png')
    fs.createReadStream('/tmp/input.png')
        .pipe(gd.watermark('/tmp/smiley.png', {x: 1, y: 0.9}))
        .pipe(outStream)

Result

output.png

[jacobtomlinson]

Any update on this? Thanks!

[jacobtomlinson]

Bump

[furagu]

@jacobtomlinson sorry man, was busy the whole weekend. Will take a look tonight.

[jacobtomlinson]

Awesome thanks!

[jacobtomlinson]

Great thank you very much.

[furagu]

You are welcome! The updated version is already available via npm.

By the way, your smiley.png has a white opaque background, which was kinda confusing :) Anyway, now that works:

var gd = require('./index.js'),
    fs = require('fs')

var outStream = fs.createWriteStream('out.png')

fs.createReadStream('in.png')
    .pipe(gd.watermark( gd.open('in.png').resize({width: 200, height: 200}) ))
    .pipe(gd.watermark('s.png'))
    .pipe(outStream)

[jacobtomlinson]

Ah thanks. I just grabbed that smiley off the interwebs for the example, I'm not actually using it.