I used ippiResizeLanczos_8u_C3R to downscale images from IP-camera to 320*240 size.
Now we have an option to get 2 streams from the same camera. One of them will be usual size (Full HD or more) and the second stream will be 320*240.
My question is:
Does ippiResizeLanczos_8u_C3R just copy image or it try to make some computations in case of equal size of source and destination image?
The function ippiResizeLanczos_8u_C3R implements a resize transform algorithm with fixed filter interpolation, so if the input and output images have the same size, it means that Lanczos filter is applied to the input image. Thus ippiResizeLanczos_8u_C3R makes some computations in case of equal size of source and destination images.
The function ippiResizeSuper_8u_C3R can be used for downscaling. This function just copies image in case of equal size of source and destination images.