Single pixel diffs are not ignored

[jwir3]

Using looks-same v3.3.0.

Note that the reference image was generated using WebGL on a Macbook Pro 2015, whereas the generated image is generated using a docker image running Ubuntu with osmesa.

looks-same configuration:

await looksSameAsync(actual, expected,
                                           {
                                             tolerance: tolerance,
                                             pixelRatio: self._getDPI(), // set to device DPI
                                             ignoreAntialiasing: true,
                                             ignoreCaret: true
                                           });

await looksSame.createDiffAsync({
        reference: this._getReferenceFilePath(),
        current: this.getActualFilePath(),
        diff: this._getDiffFilePath(),
        highlightColor: '#ff00ff',
        tolerance: tolerance,
        pixelRatio: self._getDPI(),
        ignoreAntialiasing: true,
        ignoreCaret: true
      });

reference image:

generated image:

diff:

The lower left pixel of the triangle is showing up as different, and the test is failing due to this.