Attach (recommended) or Link to PDF file here:
[backgroundimage_not_visible_anonymisiert.pdf](https://github.com/mozilla/pdf.js/files/6544725/backgroundimage_not_visible_anonymisiert.pdf)


Configuration:
- Web browser and its version: Chrome Version 90.0.4430.212 (Offizieller Build) (x86_64)
- Operating system and its version: Windows 10, MacOs BigSur
- PDF.js version: 2.5.207
- Is a browser extension: no

Steps to reproduce the problem:
1. open the document in demo viewer.js
2.

What is the expected behavior? (add screenshot)
The backgroundimage gets rendered like in Acrobat Reader
<img width="1348" alt="Bildschirmfoto 2021-05-26 um 09 44 21" src="https://user-images.githubusercontent.com/1286150/119621970-00a82480-be07-11eb-8fed-f74ac04b840b.png">

What went wrong? (add screenshot)
Backgroundimage is not rendered only some  text
<img width="987" alt="Bildschirmfoto 2021-05-26 um 09 43 57" src="https://user-images.githubusercontent.com/1286150/119621938-fab24380-be06-11eb-92ac-4ecb2c9334b1.png">




Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

constructor(canvasFactory) {
    this.canvasFactory = canvasFactory;
    this.cache = Object.create(null);
  }
  getCanvas(id, width, height, trackTransform) {
    let canvasEntry;
    if (this.cache[id] !== undefined) {
      canvasEntry = this.cache[id];
      this.canvasFactory.reset(canvasEntry, width, height);
      
      canvasEntry.context.setTransform(1, 0, 0, 1, 0, 0);
    } else {
      canvasEntry = this.canvasFactory.create(width, height);
      this.cache[id] = canvasEntry;
    }
    if (trackTransform) {
      addContextCurrentTransform(canvasEntry.context);
    }
    return canvasEntry;
  }
  clear() {
    for (const id in this.cache) {
      const canvasEntry = this.cache[id];
      this.canvasFactory.destroy(canvasEntry);
      delete this.cache[id];
    }
  }
}
function compileType3Glyph(imgData) {