Systems and methods for calculating image sharpness measurements

摘要

Imaging systems with image sensors and image processing circuitry are provided. The image processing circuitry may calculate sharpness values for a window within an image captured by the image sensors. The window may be divided into zones. A first filter may be applied to each row of each zone. A first sharpness value may be calculated by averaging the absolute values of the outputs of the first filter that are greater than a first threshold. A second sharpness value may be calculated by averaging the absolute values of the outputs of the second filter that are greater than a second threshold. A final sharpness value for each zone may be calculated by dividing the second sharpness value by the first sharpness value and multiplying the result by corresponding scalar weights. A window sharpness value may be calculated from the weighted sum of the final sharpness values of each zone.