How to Reduce the Resolution of an Image in OpenCV?

Question

So, I have an image from a digital scanner, its resolution is 26 Megapixel. I want to reduce the resolution of the image to 5 Megapixel.

Is it possible to reduce the resolution of an image without damaging the contents?

If yes, how to reduce it in OpenCV implementation?

Any help would be greatly appreciated. Thankyou

Answer 1

You can use cv2::resize()

resize(src, dst, Size(), factor, factor, interpolation);

here, interpolation can be selected as cv::INTER_LANCZOS4 to obtain best interpolation results.

factor is the sampling ratio and in order to transform from 26mp to 5mp you may need it to be 2.28

Downsampling always introduces some information and detail loss.