[javascript] Image resizing client-side with JavaScript before upload to the server

Here's a gist which does this: https://gist.github.com/dcollien/312bce1270a5f511bf4a

(an es6 version, and a .js version which can be included in a script tag)

You can use it as follows:

<input type="file" id="select">
<img id="preview">
<script>
document.getElementById('select').onchange = function(evt) {
    ImageTools.resize(this.files[0], {
        width: 320, // maximum width
        height: 240 // maximum height
    }, function(blob, didItResize) {
        // didItResize will be true if it managed to resize it, otherwise false (and will return the original file as 'blob')
        document.getElementById('preview').src = window.URL.createObjectURL(blob);
        // you can also now upload this blob using an XHR.
    });
};
</script>

It includes a bunch of support detection and polyfills to make sure it works on as many browsers as I could manage.

(it also ignores gif images - in case they're animated)

Examples related to javascript

need to add a class to an element How to make a variable accessible outside a function? Hide Signs that Meteor.js was Used How to create a showdown.js markdown extension Please help me convert this script to a simple image slider Highlight Anchor Links when user manually scrolls? Summing radio input values How to execute an action before close metro app WinJS javascript, for loop defines a dynamic variable name Getting all files in directory with ajax

Examples related to image

Reading images in python Numpy Resize/Rescale Image Convert np.array of type float64 to type uint8 scaling values Extract a page from a pdf as a jpeg How do I stretch an image to fit the whole background (100% height x 100% width) in Flutter? Angular 4 img src is not found How to make a movie out of images in python Load local images in React.js How to install "ifconfig" command in my ubuntu docker image? How do I display local image in markdown?

Examples related to resize

Numpy Resize/Rescale Image AngularJS $watch window resize inside directive Input type "number" won't resize How can I make all images of different height and width the same via CSS? How to get full width in body element Rerender view on browser resize with React How to resize image automatically on browser width resize but keep same height? PHPExcel auto size column width Automatically resize images with browser size using CSS Change form size at runtime in C#

Examples related to client-side

Getting query parameters from react-router hash fragment Single Page Application: advantages and disadvantages How to export JavaScript array info to csv (on client side)? Best practice for localization and globalization of strings and labels How can you use php in a javascript function How to create a file in memory for user to download, but not through server? Pass request headers in a jQuery AJAX GET call Image resizing client-side with JavaScript before upload to the server Print directly from browser without print popup window Sending emails with Javascript