cla*
*color-level-adjuster
cla is a small javascript image processing library for applying an automatic color level adjustment to an image at the client side . cla may improve the tonal quality of the image ( especially photos with low color range )
Library contains a single function named adjustColorLevel in a single javascript file . Library is also available as a typescript file .
adjustColorLevel function takes 2 parameters
- first parameter is an HTMLImageElement
- second parameter is the callback function that is called after raw image is downloaded & processed . Callback arguments are
- processedImage as an HTMLImageElement
- modificationRate as a number .
sample usage
var rawImage = new Image();
rawImage.src = 'sample.jpg';
// you can also select your <img> tag and assign to rawImage , example :
// rawImage = document.getElementById('your-image-id');
adjustColorLevel(rawImage , imageProcessHandler);
function imageProcessHandler(processedImage , modificationRate)
{
document.body.appendChild(rawImage);
document.body.appendChild(processedImage);
}
modificationRate is a number ranging between 0-100 which shows the amount of modification that the image processing has done . Having the modificationRate equals to 0 means that , raw image already has a high color range and processing did not change anything .
Image source of the processedImage is encoded as base64 string .
Examples
Security Restrictions
This library uses HTML5 Canvas API . In order to read data from canvas , drawn images must be in the same domain with the html file or image must have a CORS header .