Mobile Phones: Using JavaScript to make snapshots via phone camera

[ivandanko]

Hi together,

Some months ago I developed a special php web application for mobile phones.
Our customers use Samsung Galaxy xcover with Android and Opera Mobile for browsing the application.

I use a JS functionality called "navigator.getUserMedia". I think it's very powerful, but there's something I'm missing.

Look: I use "navigator.getUserMedia" to give the end user the possibility to make snapshots and upload the images to my webserver directory.
And it works fine, really!

But - and that's my problem - I haven't found out how to change resolution of these phone snapshots.

I checked the whole JavaScript code if there's a possibility to define resolution information but without any luck.
I tried to change some JS code phrases to define and configure image resolution how I want and how I need them. But no success!

Now I'm not sure if it's generally a JS problem. Could it be that the "navigator.getUserMedia" functionality doesn't have the possibilities I need?

Is anybody there who had or has the same problem?
Did anybody solve it?

Yours

Danny

[rnd me]

function thumb(src, cb) {
	var img = new Image,  max=250 ;

	img.onload = function() {

		var v = img,
			h = v.height,
			w = v.width;
		var oh = h, 
			ow = w;
		if (w > max || h > max ) {
			w = max ;
			h = Math.floor( h / (ow/max ) );
		}

		var c = document.createElement("canvas");
		c.height= h;
		c.width= w;

		var ctx = c.getContext("2d");
		ctx.drawImage(v, 0, 0, w, h);

		var i = new Image(w, h);
		cb(   c.toDataURL("image/jpeg", 0.25)  );
	
	};

	
	img.src=src;
}

this function accepts an image url and a callback, to which a re-sized and compressed jpeg's data URL is passed.
I'm not sure how you got the bits to your server, but you can "rip" the data url using "".slice() + window.atob() to get the binary data if you need it.

i set the max dimension (w or h) to 250, feel free to customize to your constraints.


if you have image data and not a url, get a blob url to feed to the function using the window.URL class.

[ivandanko]

Hi,

many thanx for your help. This was the code I needed:

var c = document.createElement("canvas");
c.height= h;
c.width= w;
ctx.drawImage(v, 0, 0, w, h);

It works fine! Thank you again.

Thomas