Png with transparency is added twice

[wasa4587]

Bug Report

Description of the problem

When I try to insert a png with transparency into the document, the image is inserted twice.

this is the image:
https://drive.google.com/file/d/1Paci2YPG0PAvnvNgGlVazkn3cL8txICt/view?usp=sharing

this is the output pdf
https://drive.google.com/file/d/1O3sRSiHnLCpRkiflb7tjzWfxGh7xbvSf/view?usp=sharing

Code sample

const PDFDocument = require('pdfkit');
const fs = require('fs');

  const doc = new PDFDocument( {
    layout: 'portrait',
    size: 'letter',
    margin: 0,
  });

  doc.image('./google0.026317087946030382.png', 0 ,0 , { width: 150, height: 100});

  const pdfFile = `./output.pdf`;
  doc.pipe(fs.createWriteStream(pdfFile));
  doc.end();  

Your environment

• pdfkit version: ^0.8.3
• Node version: v8.10.0
• Operating System: ubuntu:16.04 and Windows 10

[sboudouk]

Same issue here.

[swftvsn]

we use https://github.com/lovell/sharp to preprocesses image on the fly to produce consistent results across wide variety of images. It handles multiple formats so we can accept images in many formats and produce predictable pdfs without worrying about users supplying webp or other formats.

[sboudouk]

A quickfix found according to #339 , saving as PNG24 and not as sRGB (with photoshop, for example) makes the issue disappear.

[wasa4587]

I just tested #891, it fixes my issue, nevertheless is not deployed in npm yet

[ggaabe]

I used Imagemagick to produce consistent results by flattening the PNG and then converting it to jpg:

const spawn = require('child-process-promise').spawn;

const tempLocalFile = path.join(os.tmpdir(), filePath);
//load image into tempLocalFile location ^^
const tempLocalThumbFile = path.join(os.tmpdir(), thumbFilePath + ".jpg");

      return spawn('convert', [tempLocalFile, '-thumbnail', `${THUMB_MAX_WIDTH}x${THUMB_MAX_HEIGHT}>`, '-flatten', tempLocalThumbFile], {capture: ['stdout', 'stderr']});

[blikblum]

Version 0.9 should fix thix