Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

k = bufferLength;
      var columns = this.columns;
      for (i = 0; i < columns; ++i) {
        for (var kk = 0; kk < colors; ++kk) {
          if (inbits < bits) {
            inbuf = (inbuf << 8) | (rawBytes[j++] & 0xff);
            inbits += 8;
          }
          compArray[kk] =
            (compArray[kk] + (inbuf >> (inbits - bits))) & bitMask;
          inbits -= bits;
          outbuf = (outbuf << bits) | compArray[kk];
          outbits += bits;
          if (outbits >= 8) {
            buffer[k++] = (outbuf >> (outbits - 8)) & 0xff;
            outbits -= 8;
          }
        }
      }
      if (outbits > 0) {
        buffer[k++] =
          (outbuf << (8 - outbits)) + (inbuf & ((1 << (8 - outbits)) - 1));
      }
    }
    this.bufferLength += rowBytes;
  };
  PredictorStream.prototype.readBlockPng = function predictorStreamReadBlockPng() {
    var rowBytes = this.rowBytes;
    var pixBytes = this.pixBytes;
    var predictor = this.str.getByte();