Given a data URL, you can create an image (either on the page or purely in JS) by setting the src of the image to your data URL. For example: var img = new Image; img.src = strDataURI; The drawImage() method of HTML5 Canvas Context lets you copy all or a portion of an image … Read more
Yes, use the File API, then you can process the images with the canvas element. This Mozilla Hacks blog post walks you through most of the process. For reference here’s the assembled source code from the blog post: // from an input element var filesToUpload = input.files; var file = filesToUpload[0]; var img = document.createElement(“img”); … Read more
You should be aware of a few key factors… First, there are two types of compression: Lossless and Lossy. Lossless means that the image is made smaller, but at no detriment to the quality. Lossy means the image is made (even) smaller, but at a detriment to the quality. If you saved an image in … Read more
Support for CSS filters has landed in Webkit. So we now have a cross-browser solution. img { filter: gray; /* IE6-9 */ -webkit-filter: grayscale(1); /* Google Chrome, Safari 6+ & Opera 15+ */ filter: grayscale(1); /* Microsoft Edge and Firefox 35+ */ } /* Disable grayscale on hover */ img:hover { -webkit-filter: grayscale(0); filter: none; … Read more
See the Create a video slideshow from images – FFmpeg If your video does not show the frames correctly If you encounter problems, such as the first image is skipped or only shows for one frame, then use the fps video filter instead of -r for the output framerate ffmpeg -r 1/5 -i img%03d.png -c:v … Read more
To the point, it has to be accessible by a public URL. Thus, the <img src> must ultimately refer a http:// URI, not something like a file:// URI or so. Ultimately, the HTML source is executed at enduser’s machine and images are downloaded individually by the webbrowser during parsing the HTML source. When the webbrowser … Read more
The method could vary depending on your needs. Here are 3 ways to calculate Luminance: Luminance (standard for certain colour spaces): (0.2126*R + 0.7152*G + 0.0722*B) source Luminance (perceived option 1): (0.299*R + 0.587*G + 0.114*B) source Luminance (perceived option 2, slower to calculate): sqrt( 0.241*R^2 + 0.691*G^2 + 0.068*B^2 ) → sqrt( 0.299*R^2 + … Read more
Dynamic variables Note that whilst this is possible, it’s considered to be bad programming (see for instance here, or this blog by Loren and even the Mathworks in their documentation tell you not to do this). It would be much better to load your images directly into either a 3D array or a cell structure, … Read more
Below are three approaches to solving this problem (and there are many others). The first is a standard approach in computer vision, keypoint matching. This may require some background knowledge to implement, and can be slow. The second method uses only elementary image processing, and is potentially faster than the first approach, and is straightforward … Read more
You need to read the dat file into matlab, set MrPort and Reco variables and then save to mat file: >> save(‘myMatFile.mat’, ‘MrPort’, ‘Reco’ );