In this section you will learn about the image processing (manipulation) functions inside OpenCV.

Basic Drawing

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

We will learn how to draw simple geometry with OpenCV!
Random generator and text with OpenCV

Compatibility: > OpenCV 2.0

Author: Ana Huamán

We will draw some fancy-looking stuff using OpenCV!
Smoothing Images

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Let's take a look at some basic linear filters!
Eroding and Dilating

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Let's change the shape of objects!
More Morphology Transformations

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Here we investigate different morphology operators
Hit-or-Miss

Languages: C++, Java, Python

Compatibility: > OpenCV 2.4

Author: Lorena García

Learn how to find patterns in binary images using the Hit-or-Miss operation
Extract horizontal and vertical lines by using morphological operations

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Theodore Tsesmelis

Here we will show how we can use different morphological operators to extract horizontal and vertical lines
Image Pyramids

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

What if I need a bigger/smaller image?
Basic Thresholding Operations

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

After so much processing, it is time to decide which pixels stay
Thresholding Operations using inRange

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Rishiraj Surti

Thresholding operations using inRange function.
Making your own linear filters!

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn to design our own filters by using OpenCV functions
Adding borders to your images

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to pad our images
Sobel Derivatives

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to calculate gradients and use them to detect edges
Laplace Operator

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn about the Laplace operator and how to detect edges with it
Canny Edge Detector

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn a sophisticated alternative to detect edges
Hough Line Transform

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to detect lines
Hough Circle Transform

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to detect circles
Remapping

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to manipulate pixels locations
Affine Transformations

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to rotate, translate and scale our images
Histogram Equalization

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to improve the contrast in our images
Histogram Calculation

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to create and generate histograms
Histogram Comparison

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn to calculate metrics between histograms
Back Projection

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to use histograms to find similar objects in images
Template Matching

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to match templates in an image
Finding contours in your image

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to find contours of objects in our image
Convex Hull

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to get hull contours and draw them
Creating Bounding boxes and circles for contours

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to obtain bounding boxes and circles for our contours
Creating Bounding rotated boxes and ellipses for contours

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to obtain rotated bounding boxes and ellipses for our contours
Image Moments

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn to calculate the moments of an image
Point Polygon Test

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Ana Huamán

Where we learn how to calculate distances from the image to contours
Image Segmentation with Distance Transform and Watershed Algorithm

Languages: C++, Java, Python

Compatibility: > OpenCV 2.0

Author: Theodore Tsesmelis

Where we learn to segment objects using Laplacian filtering, the Distance Transformation and the Watershed algorithm.
Out-of-focus Deblur Filter

Languages: C++

Compatibility: > OpenCV 2.0

Author: Karpushin Vladislav

You will learn how to recover an out-of-focus image by Wiener filter.
Motion Deblur Filter

Languages: C++

Compatibility: > OpenCV 2.0

Author: Karpushin Vladislav

You will learn how to recover an image with motion blur distortion using a Wiener filter.
Anisotropic image segmentation by a gradient structure tensor

Languages: C++

Compatibility: > OpenCV 2.0

Author: Karpushin Vladislav

You will learn how to segment an anisotropic image with a single local orientation by a gradient structure tensor.
Periodic Noise Removing Filter

Languages: C++

Compatibility: > OpenCV 2.0

Author: Karpushin Vladislav

You will learn how to remove periodic noise in the Fourier domain.