Synthetic Aperture Radar on the Jetson TX1

John MelonakosArrayFire, Case Studies, Computer Vision, CUDA, Image Processing 1 Comment

Researchers at Peter the Great St. Petersburg Polytechnic University have implemented a synthetic aperture radar processing on the Jetson TX1 Platform using ArrayFire as described in this paper. The paper introduces SAR as “a remote sensing technique producing high-resolution radar images of the Earth’s surface. SAR technology allows obtaining wide swath radar images of objects at a considerable distance regardless of the weather and lighting conditions. It can be used by unmanned aerial vehicles and space satellites. Thus, SAR technology allows solving various problems, such as: detecting small objects (vehicles, airplanes, ships), assessing the state of railways, airfields, seaports, mapping an area, assisting in geological exploration, mapping vegetation, detecting oil spills and pollution as well as many other tasks.” The …

Thrombotherm: Analyzing Blood Platelets with ArrayFire

John MelonakosArrayFire, Case Studies, Image Processing Leave a Comment

The Thrombotherm project by Catalysts is developing a method to analyze blood platelets by means of cell microscopy in real time and to classify them according to their activation state. ArrayFire enabled faster overall research project times and real-time analysis on video data. This project represents an enormous extension of thrombocyte diagnotics, especially through significantly accelerated analysis times. Faster analyses enabled university research collaborators from the University of Applied Sciences OÖ and the Ludwig Boltzmann Institute to shorten research project times. The project has three main parts: Detect cell morphology in real-time Thombotherm makes it possible to mathematically determine and categorize the cell boundaries by means of transmitted light microscopy. The software distinguishes between “fried-egg”-shaped cells and “spider”-shaped cells. This is used …

Feature detection and tracking using ArrayFire

Brian KloppenborgArrayFire, C/C++, Image Processing Leave a Comment

A few weeks ago we added some computer vision functionality to our open source ArrayFire GPU computing library. Specifically, we implemented the FAST feature extractor, BRIEF feature point descriptor, ORB multi-resolution scale invariant feature extractor, and a Hamming distance function. When combined, these functions enable you to find features in videos (or images) and track them between successive frames.

Conway’s Game of Life using ArrayFire

Shehzan MohammedArrayFire, CUDA, Image Processing, Open Source, OpenGL 4 Comments

Conway’s Game of Life is a popular zero player cellular automaton devised by the John Horton Conway in 1970. The game makes for a fun evolution as the player sets the initial condition and then observes the evolution of the game. Each cell has 2 states: live or dead. There are 4 simple rules that determine this: Any live cell with fewer than two live neighbours dies, as if caused by under-population. Any live cell with two or three live neighbours lives on to the next generation. Any live cell with more than three live neighbours dies, as if by overcrowding. Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction. From a programmer’s …

Image editing using ArrayFire: Part 3

Pradeep GarigipatiArrayFire, C/C++, CUDA, Image Processing, OpenCL 1 Comment

Today, we will be doing the third post in our series Image editing using ArrayFire. References to old posts are available below. * Part 1 * Part 2 In this post, we will be looking at the following operations. Image Histogram Simple Binary Theshold Otsu Threshold Iterative Threshold Adaptive Binary Threshold Emboss Filter Today’s post will be mostly dominated by different types of threshold operations we can achieve using ArrayFire. Image Histogram We have a built-in function in ArrayFire that creates a histogram. The input image was converted to gray scale before histogram calculation as our histogram implementation works for vector and 2D matrices only. In case, you need histogram for all three channels of a color image, you can …

Image editing using ArrayFire: Part 2

Pradeep GarigipatiArrayFire, Image Processing 10 Comments

A couple of weeks back, we did a post on a few image editing functions using ArrayFire library. Today, we shall be doing the second post in the series Image Editing using ArrayFire. We will be looking at the following operations today. Image distortion Noise addition Noise reduction Edge filters Boundary extraction Difference of gaussians Code and sample input/outputs corresponding to each operation are described below. Image distortion We will be looking at spread and pick filters in this section. Both of these filters are fundamentally the same, they replace each pixel in the original image with one of it’s neighboring pixels. How the neighbor is chosen is essentially the difference between spread and pick. Both of these functions use …

Image editing using ArrayFire

Pradeep GarigipatiArrayFire, Image Processing 2 Comments

In this post, we will be looking at the following simple image editing operations using the ArrayFire library. contrast modification brightness modification translation digital zoom alpha blending unsharp mask Code required to do each operation and the corresponding input/output sample are given below in their corresponding sections. All the operations are built using some existing image manipulation functions and the awesome element-wise operations in ArrayFire. Contrast modification /** * contrast value should be in the range [-1,1] **/ void changeContrast(array &in, const float contrast) { float scale = tan((contrast+1)*Pi/4); in = ((in/255.0f – 0.5f) * scale + 0.5f) * 255.0f; } Brightness modification /** * brightness value should be in the range [0,1] **/ void changeBrightness(array &in, const float brightness, …