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.

const { context: ctx } = this.cachedCanvases.getCanvas(
        "isFontSubpixelAAEnabled",
        10,
        10
      );
      ctx.scale(1.5, 1);
      ctx.fillText("I", 0, 10);
      const data = ctx.getImageData(0, 0, 10, 10).data;
      let enabled = false;
      for (let i = 3; i < data.length; i += 4) {
        if (data[i] > 0 && data[i] < 255) {
          enabled = true;
          break;
        }
      }
      return shadow(this, "isFontSubpixelAAEnabled", enabled);
    }
    showText(glyphs) {
      const current = this.current;
      const font = current.font;
      if (font.isType3Font) {
        return this.showType3Text(glyphs);
      }
      const fontSize = current.fontSize;
      if (fontSize === 0) {