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.

let pattern;
      if (IR[0] === "TilingPattern") {
        const color = IR[1];
        const baseTransform =
          this.baseTransform || this.ctx.mozCurrentTransform.slice();
        const canvasGraphicsFactory = {
          createCanvasGraphics: ctx => {
            return new CanvasGraphics(
              ctx,
              this.commonObjs,
              this.objs,
              this.canvasFactory
            );
          },
        };
        pattern = new TilingPattern(
          IR,
          color,
          this.ctx,
          canvasGraphicsFactory,
          baseTransform
        );
      } else {
        pattern = getShadingPattern(IR);
      }
      return pattern;
    }
    setStrokeColorN() {