3
I am developing a system where the user can make small adjustments in images, and can rotate and cut currently. Before this whole part was being done through coordinates, where I sent the parameters to the server and, from there, processed the images.
Now I’m using the canvas
, where I can already make these edits directly in the client (browser) to, later, send the already edited final image.
To see the power of canvas
thought to add other features, such as increase/decrease the brightness of some images.
Is there any way to control the brightness of the image through the canvas
?
Please, if the answer involves mathematical calculations, I would like an explanation, not just the code that generates the desired result.
Let’s use again the image of the parrot as an example:
window.addEventListener('load', onLoadPage)
function qs(selector) {
return document.querySelector(selector);
}
function onLoadPage()
{
var canvas = qs('#canvas');
var image = qs('#image');
canvas.height = image.height;
canvas.width = image.width;
var context = canvas.getContext('2d');
context.drawImage(image, 0, 0);
}
<img id="image" 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'>
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