I want to get a portion of pixels in a region of interest (ROI) of each frame while the camera is previewing. I'm obtaining the bitmap from the TextureView and calculating the mean value of that region using a 'for' cycle. The process is slow if I do it in a large ROI holding the default resolution of the TextureView (2200x1080 aprox), so I want to know if there is a way to set this resolution lower in order to obtain speed in the for cycle with less pixels but more area.
Also I want to know if there is another way to do this process. All I want is to reach more area in screen keeping a good frame rate (maybe 20-25 fps) when I get the mean pixel value of that region.