focus peak 찾아내기

결론(?)은 HPF(High Pass Filter) 인가?

The simplest way to detect microcontrast is through a high pass filter (HPF). In the areas in focus, the detail will trigger a threshold set in the HPF, while out of focus areas wont's do so for being totally blurred in terms of high spatial frequencies.

[링크 : http://forum.luminous-landscape.com/index.php?topic=56246.0]

The simple recipe is to convolve with a Laplacian of Gaussian kernel (3x3, with 8 in the middle surrounded by -1 and take the abs(result)) .

[링크 : http://photo.stackexchange.com/questions/32388/how-can-i-focus-peak-a-photograph]