Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

Emulating cross-processing

Cross-processing produces a strong blue or greenish-blue tint in shadows and a strong yellow or greenish-yellow in highlights. Black and white are not necessarily preserved. Also, the contrast is very high. Cross-processed photos take on a sickly appearance. People look jaundiced, while inanimate objects look stained. Let's edit filters.py and add the following implementation of a cross-processing filter:

class BGRCrossProcessCurveFilter(BGRCurveFilter):    """A filter that applies cross-process-like curves to BGR."""    def __init__(self, dtype=numpy.uint8):        BGRCurveFilter.__init__(            self,            bPoints = [(0,20),(255,235)],            gPoints = [(0,0),(56,39),(208,226),(255,255)],            rPoints = [(0,0),(56,22),(211,255),(255,255)], dtype ...