Tag Archives: opencv

Introduction to OpenCV

The easiest way to learn OpenCV is to buy & read the book “Learning OpenCV” from O’Reilly. Otherwise you can follow these instructions depending on your C/C++ compiler. This webpage explains how to setup OpenCV v2.1.0. There is a newer version of OpenCV available (v2.2.0), but it

ARM’s 64-bit mode (AArch64) ARMv8)

Good web presentation about AArch64: http://people.linaro.org/~rikuvoipio/aarch64-talk/#/ All AArch64 instructions are 32-bits long (instead of some 16-bit and some 32-bit). ARMv8 64-bit mode has doubled the register widths (64-bit instead of 32-bit) but also doubled the number of general CPU registers (32 instead of 16). When only

Do all versions of OpenCV run at the same speed?

OpenCV was originally created by Intel to demonstrate how fast Intel CPUs can perform, and therefore the speed performance of OpenCV was of crucial importance. However, OpenCV has recently changed from a low-level image processing C library built for maximum speed, to a higher-level computer

Draw graphs using OpenCV

Here is a basic graphing library to allow plotting graphs on the screen or into an image using OpenCV. This can be very useful to view the contents of a numerical array, such as during testing of an algorithm. This “library” is just a collection

Rotating or Resizing an Image in OpenCV

The page will show you how to do some common image transformations in OpenCV, such as rotating an image, cropping an image or resizing an image without changing its aspect ratio. Rotating an Image in OpenCV The function below will rotate an image using cvGetQuadrangleSubPix(),

Color Conversions

The RGB color format can represent any standard color or brightness using a combination of Red, Green and Blue components. For efficiency, this is typically stored as a 24-bit number using 8-bits for each color component (0 to 255) so that for example, White is


OpenCV is a great library for creating Computer Vision software using state-of-the-art techniques, and is freely available for Windows, Linux, Mac and even Android & iPhone. OpenCV was originally designed by Intel in 1999 to show how fast Intel CPUs can run. So most of