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 BORDER_SIZE = 2;
    const offsetX = Math.floor(this._bounds[0]);
    const offsetY = Math.floor(this._bounds[1]);
    const boundsWidth = Math.ceil(this._bounds[2]) - offsetX;
    const boundsHeight = Math.ceil(this._bounds[3]) - offsetY;
    const width = Math.min(
      Math.ceil(Math.abs(boundsWidth * combinedScale[0] * EXPECTED_SCALE)),
      MAX_PATTERN_SIZE
    );
    const height = Math.min(
      Math.ceil(Math.abs(boundsHeight * combinedScale[1] * EXPECTED_SCALE)),
      MAX_PATTERN_SIZE
    );
    const scaleX = boundsWidth / width;
    const scaleY = boundsHeight / height;
    const context = {
      coords: this._coords,
      colors: this._colors,
      offsetX: -offsetX,
      offsetY: -offsetY,
      scaleX: 1 / scaleX,
      scaleY: 1 / scaleY,
    };
    const paddedWidth = width + BORDER_SIZE * 2;
    const paddedHeight = height + BORDER_SIZE * 2;
    const tmpCanvas = cachedCanvases.getCanvas(
      "mesh",
      paddedWidth,
      paddedHeight,
      false