I'm sorry if it's a duplicate, I found lots of issues with gradients but none of the open ones looks similar.
It's apparently the PDF code `/Matrix [440 0 0 -200 20 220]` (line 44 in both files) that causes the problem.

**Configuration:**
- Web browser and its version: Chrome 54
- Operating system and its version: Windows 10
- PDF.js version: 1.6.343

**Steps to reproduce the problem:**
Open attached files:
[radial.pdf](https://github.com/mozilla/pdf.js/files/610302/radial.pdf)
[linear.pdf](https://github.com/mozilla/pdf.js/files/610300/linear.pdf)

**What is the expected behavior?** (Adobe Reader 11)
![image](https://cloud.githubusercontent.com/assets/17966696/20583379/fa80d780-b1f1-11e6-85d2-62dd6970a08c.png)

**What went wrong?** (mozilla.github.io/pdf.js/web/viewer.html)
Gradients aren't correctly transformed
![image](https://cloud.githubusercontent.com/assets/17966696/20583361/cf5bb8a4-b1f1-11e6-9479-9cc606b41187.png)

tmpCtx.clearRect(0, 0, newWidth, newHeight);
        tmpCtx.drawImage(
          imgToPaint,
          0,
          0,
          paintWidth,
          paintHeight,
          0,
          0,
          newWidth,
          newHeight
        );
        imgToPaint = tmpCanvas.canvas;
        paintWidth = newWidth;
        paintHeight = newHeight;
        tmpCanvasId = tmpCanvasId === "prescale1" ? "prescale2" : "prescale1";
      }
      ctx.drawImage(
        imgToPaint,
        0,
        0,
        paintWidth,
        paintHeight,
        0,
        -height,
        width,
        height
      );
      if (this.imageLayer) {
        const position = this.getCanvasPosition(0, -height);