I'm curious on how each of these estimations for how in-focus an image is work, and how they compare with each other? The laplacian seems to quantify the rate in which the brightness of an image changes from pixel to pixel. The gradient I believe does something pretty similar, measuring the rate of change of, in this case I'm guessing, the brightness. Are there any pros/cons to each of these listed methods of determining focus?
KevinXu02
The Laplacian operator is a 2D isotropic measure of the 2nd spatial derivative of an image.The variance of the Laplacian can be used as a measure of focus - a higher variance indicates a more in-focus image.The gradient measures the directional change in the intensity or color in an image.The average or maximum gradient magnitude can be used to estimate focus.
I'm curious on how each of these estimations for how in-focus an image is work, and how they compare with each other? The laplacian seems to quantify the rate in which the brightness of an image changes from pixel to pixel. The gradient I believe does something pretty similar, measuring the rate of change of, in this case I'm guessing, the brightness. Are there any pros/cons to each of these listed methods of determining focus?
The Laplacian operator is a 2D isotropic measure of the 2nd spatial derivative of an image.The variance of the Laplacian can be used as a measure of focus - a higher variance indicates a more in-focus image.The gradient measures the directional change in the intensity or color in an image.The average or maximum gradient magnitude can be used to estimate focus.