PDF.js displays blurry plots in PDF documents, e.g.

http://arxiv.org/pdf/1202.5344v1.pdf

When viewed in Chrome or Adobe Acrobat all the plots show sharp-edged squares. When viewed in Preview or PDF.js, all the squares show as blurry pixelated blobs.

}
    setCharWidthAndBounds(xWidth, yWidth, llx, lly, urx, ury) {
      
      
      this.ctx.rect(llx, lly, urx - llx, ury - lly);
      this.clip();
      this.endPath();
    }
    
    getColorN_Pattern(IR) {