Smoothing Images

This involves applying Blur, GaussianBlur, medianBlur, and bilateral Filter.

Eroding and Dilating

It can apply two very common morphology operators − Dilation and Erosion.

Morphology Transformations

OpenCV function morphologyEx to apply Morphological Transformation such as opening, closing, TopHat, and BlackHat etc.

Image Pyramids

OpenCV functions pyrUp and pyrDown to down sample or up sample a given image.

Basic Thresholding Operations

It can perform basic thresholding operations using OpenCV function threshold.

Adding borders to your images

OpenCV function copyMakeBorder is used to set the borders(extra padding to your image).

Remapping

In OpenCV, the function remap offers a simple remapping implementation.

Histogram Calculation

For simple purposes, OpenCV implements the function calcHist, which calculates the histogram of a set of arrays (usually images or image planes). It can operate with up to 32 dimensions.