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I am not able to find a proper way to read an image from a URL and upload it using JavaScript/Ajax.

Suppose there is a URL: https://pbs.twimg.com/profile_images/1580483969/parisjs_transparent.png.

I should be able to upload it now, but I guess to upload first I need to download it, so what will be the procedure?

3 Answers 3

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If the remote server allows CORS requests, it possible to download a remote image and read its contents. If the remote server does not allow CORS, the image can be shown (using a standard <img src=".."> tag), but the content cannot be read - the canvas gets tainted.

Download image from remote URL using JavaScript when CORS is enabled

function getImageFormUrl(url, callback) { var img = new Image(); img.setAttribute('crossOrigin', 'anonymous'); img.onload = function (a) {	var canvas = document.createElement("canvas");	canvas.width = this.width;	canvas.height = this.height;	var ctx = canvas.getContext("2d");	ctx.drawImage(this, 0, 0);	var dataURI = canvas.toDataURL("image/jpg");	// convert base64/URLEncoded data component to raw binary data held in a string	var byteString;	if (dataURI.split(',')[0].indexOf('base64') >= 0)	byteString = atob(dataURI.split(',')[1]);	else	byteString = unescape(dataURI.split(',')[1]);	// separate out the mime component	var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];	// write the bytes of the string to a typed array	var ia = new Uint8Array(byteString.length);	for (var i = 0; i < byteString.length; i++) {	ia[i] = byteString.charCodeAt(i);	}	return callback(new Blob([ia], { type: mimeString })); } img.src = url; } getImageFormUrl('https://upload.wikimedia.org/wikipedia/commons/thumb/b/b4/The_Sun_by_the_Atmospheric_Imaging_Assembly_of_NASA%27s_Solar_Dynamics_Observatory_-_20100819.jpg/628px-The_Sun_by_the_Atmospheric_Imaging_Assembly_of_NASA%27s_Solar_Dynamics_Observatory_-_20100819.jpg', function (blobImage) {	var formData = new FormData();	formData.append('key1', 'value1');	formData.append('key2', 'value2');	formData.append('key2', 'value3');	formData.append('imageToUpload', blobImage);	console.log(blobImage);	//use formData in "data" property in $.ajax	//$.ajax({	//blabla: blabla,	//data: formData,	//blabla: blabla	//}}) });

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Comments

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Let server download/upload your image. What you need to do is to create a text input field for image URL. Than via AJAX you send to backend the URL only and server gets its contents.

2 Comments

text input field or file input field? then I just need to send the image url to the server right?
Just a text input to paste the url. Than you send it to PHP and there you get the image content. Check this Q/A.
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@DheerajAgrawal

see this example: http://jsfiddle.net/WQXXT/3004/

you should customize that, where it says:

alert('start upload script here'); 

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