drwaImage with scale or crop render very blur when export pdf file

[saberjsd]

drwaImage with scale or crop render very blur.

Here is result PDF

This is preview with 200%:

I wite a demo for show my problem for export PDF.

const exportPdf = async () => {
  const { createCanvas, loadImage } = require('canvas');
  const fs = require('fs');
  const path = require('path')
  let canvasWidth = 200;
  let canvasHeight = 200;
  const canvas = createCanvas(canvasWidth, canvasHeight, 'pdf');
  const ctx = canvas.getContext('2d');
  // image is a 800 x 800 px png 
  const imgUrl = "http://capcium.com/wp-content/themes/capcium/dist/images/-placeholders/img-example-square.png" 
  let img = await loadImage(imgUrl);
  const padding = 100;

  ctx.scale(0.1, 0.1)
  // draw origin image
  ctx.drawImage(img, padding, padding);
  // draw image with scale
  ctx.drawImage(img, img.width + padding * 2, padding, img.width - 1, img.height - 1);
  // draw image with crop
  ctx.drawImage(img, 0, 0, img.width - 1, img.height - 1, padding, img.height + padding * 2, img.width, img.height);

  const outPath = path.join(__dirname, `./output_${+new Date()}.pdf`)
  canvas.createPDFStream().pipe(fs.createWriteStream(outPath));
  console.log('end')
}

exportPdf()

[saberjsd]

It's not very clear when you zoom in. Because draw image with scale or crop, node-canvas will create a temporary canvas to draw on and then draw onto the PDF canvas. The code about this is in CanvasRenderingContext2d.cc needsExtraSurface of line 1300. Only when drawing the original image, is the complete image.

[saberjsd]

Who can help me, please

[saberjsd]

@tj @LinusU @zbjornson @TooTallNate @asturur Hello, contributors! Who can help me, please!

[thedang]

Hi @saberjsd, do you have solution for issue ?