To elaborate a bit on deltheil’s answer: Signal to noise. For many applications of image processing, color information doesn’t help us identify important edges or other features. There are exceptions. If there is an edge (a step change in pixel value) in hue that is hard to detect in a grayscale image, or if we … Read more
A quick guide to Caffe’s convert_imageset Build First thing you must do is build caffe and caffe’s tools (convert_imageset is one of these tools). After installing caffe and makeing it make sure you ran make tools as well. Verify that a binary file convert_imageset is created in $CAFFE_ROOT/build/tools. Prepare your data Images: put all images … Read more
In computer vision, there’s very often no perfect, universal way of doing something. Most often, we just try an operator, see its results and check whether they fit our needs. It’s true for gradient computation too: Sobel operator is one of many ways of computing an image gradient, which has proved its usefulness in many … Read more
There’s already an example of how to do rectangle detection in OpenCV (look in samples/squares.c), and it’s quite simple, actually. Here’s the rough algorithm they use: 0. rectangles <- {} 1. image <- load image 2. for every channel: 2.1 image_canny <- apply canny edge detector to this channel 2.2 for threshold in bunch_of_increasing_thresholds: 2.2.1 … Read more
You may want to check out the answers to these similar question: Image processing language/environment
I stumbled upon this answer while I was searching for a way to automatically compute Canny’s threshold values. Hope this helps anyone who comes looking for a good method for determining automatic threshold values for Canny’s algorithm… If your image consists of distinct foreground and background, then the edge of foreground object can use extracted … Read more
The easiest solution would be to normalize all of your images, both for training and testing, to have the same resolution. Also the character in each image should be about the same size. It is also a good idea to use greyscale images, so each pixel would give you just one number. Then you could … Read more
To remove the alpha channel from single image use this command: convert input.png -alpha off output.png To remove the alpha channel from all images inside a folder, make use find to first find all PNG files, and then run ‘m through convert: find . -name “*.png” -exec convert “{}” -alpha off “{}” \; Please test … Read more
Read http://golang.org/pkg/image // you need the image package, and a format package for encoding/decoding import ( “bytes” “image” “image/jpeg” // if you don’t need to use jpeg.Encode, use this line instead // _ “image/jpeg” “github.com/nfnt/resize” ) // Decoding gives you an Image. // If you have an io.Reader already, you can give that to Decode … Read more
I use this command line to do what are describing: convert.exe <filename>.psd -set dispose Background -coalesce <outfilename>.png