Using Gradient Layer Masks in GIMP

Some simple notes on how to seamlessly blend images in GIMP using gradient based layer masks. INPUT IMAGES 4 images with only different shutter speeds: PROCESS Open all images as separate layers in a new GIMP canvas: Right click a layer > "Add layer mask" > choose default "White full opacity" > Add: Now select the Blend Tool: Click the arrows to "Reverse" the gradient; choose "Bi-linear" shape mode: In this step I'll focus on the bottom layer only... (so hide the other Read more [...]

GPU Convolutions: OpenCV GPU and LibJacket – Part 2

This is a response to my earlier post comparing OpenCV's gpu::convolve() and LibJacket's jkt::conv2() convolution functions, at various image and kernel sizes. That post generated a lot of traffic, most notably from the OpenCV developer community. Taking note of this, it seems that the folks at Willow Garage have re-vamped their GPU convolutions and posted their own set of benchmarks using their updated routines. While the benchmarks I ran highlighted some performance issues in OpenCV - which the Read more [...]

OpenCV vs. LibJacket: GPU Sobel Filtering

Update: LibJacket has been renamed to  ArrayFire. In response to a comment on a previous post about integrating LibJacket into an OpenCV project, below is just a simple FYI performance comparison of OpenCV's GPU Sobel filter versus LibJacket's conv2 convolution filter (with a sobel kernel)... This is an evolutionary post, so be sure to scroll all the way down to see more comparisons... Update (10/24/2011): Round 2     Test system: [via /proc/cpuinfo]: Intel(R) Core(TM) i7 CPU Read more [...]

Image processing with LibJacket + OpenCV

Update: one year later: ArrayFire+OpenCV The OpenCV library is the de-facto standard for doing computer vision and image processing research projects. OpenCV includes several hundreds of computer vision algorithms, aimed for use in real-time vision applications. LibJacket is a matrix library built on CUDA. LibJacket offers hundreds of general matrix and image processing functions, all running on the GPU. The syntax is very high level and easy to use. LibJacket with OpenCV For anyone out there Read more [...]

Awesome National Geographic Script in GIMP

After installing the new plug-in registry for GIMP, I stumbled upon the amazing National Geographic Script. It is incredible! This script simulates high quality, vivid photos - like the ones from the National Geographic magazine. It uses a configurable mixture of shadow recovery, sharpening, local contrast, and various color overlay layers. The script is buried under: Filters > Generic > National Geographic. The default settings usually work for me, but play around with the opacity of the Read more [...]