Class CLIPTest

Test/astc_test_functional.py:238–1434

Command line interface positive tests.

class CLIPTest(CLITestBase):
    '''
    Command line interface positive tests.
    '''
    # pylint: disable=too-many-public-methods

    def compare(self, image1: Path, image2: Path) -> bool:
        '''
        Utility function to compare two images.

        Note that this comparison tests only decoded color values; file
        metadata is ignored, and encoding methods are not compared.

        Args:
            image1: Path to the first image.
            image2: Path to the second image.

        Return:
            True if the images are the same, False otherwise.
        '''
        # Use Any here because PIL interface doesn't have clean types
        img1: Any = Image.open(image1)
        img2: Any = Image.open(image2)

        # Images must have same size
        if img1.size != img2.size:
            return False

        # Images must have same number of color channels
        if img1.getbands() != img2.getbands():
            # ... unless the only different is alpha
            self.assertEqual(img1.getbands(), ('R', 'G', 'B'))
            self.assertEqual(img2.getbands(), ('R', 'G', 'B', 'A'))

            # ... and the alpha is always one
            bands = img2.split()
            alpha_hist = bands[3].histogram()
            self.assertEqual(sum(alpha_hist[:-1]), 0)

            # Generate a version of img2 without alpha
            img2 = Image.merge('RGB', (bands[0], bands[1], bands[2]))

        # Compute sum of absolute differences
        dat1 = numpy.array(img1)
        dat2 = numpy.array(img2)
        sad = numpy.sum(numpy.abs(dat1 - dat2))
        return sad == 0

    def get_channel_rmse(self, image1: Path, image2: Path) -> list[float]:
        '''
        Get the channel-by-channel root mean square error.

        Images must have same channel count.

        Args:
            image1: Path to the first image.
            image2: Path to the second image.