Question

i. How can you reduce the effects of aliasing during image interpolation (in the case of most typical images and interpolation schemes)?

ii. Explain why this works (in most of the typical cases).

Answer 1

Hey there!

In python if you are enlarging the image, you should prefer to use INTER_LINEAR or INTER_CUBIC image interpolation technique. If you are shrinking the image, you should prefer to use INTER_AREA interpolation.

Cubic interpolation works because it is computationally more complex, and hence slower than linear interpolation. However, the quality of the resulting image will be higher.

Here are some of the possible interpolation in openCV :

• INTER_NEAREST – a nearest-neighbor interpolation
• INTER_LINEAR – a bilinear interpolation (which is used by default)
• INTER_AREA – resampling using pixel area relation. It may be a preferred method for image decimation, as it gives moire’-free results. But when the image is zoomed, it is similar to the INTER_NEAREST method.
• INTER_CUBIC – a bicubic interpolation over 4×4 pixel neighborhood
• INTER_LANCZOS4 – a Lanczos interpolation over 8×8 pixel neighborhood

I hope it helps. Cheers :)