how to convert byte array to image from javascript

Question

0.00/5 (No votes)

See more:

Javascript

how to get byte array to image in javascript
pls help me

Regards
Elaya

Posted 16-Apr-13 1:04am

Elayaraja Ponnusamy

Add a Solution

Comments

Zoltán Zörgő 16-Apr-13 7:15am

Forget it

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

enhzflep · Answer 1 · 2013-04-16T02:19:00

I normally wouldn't bother with such a poorly written question.
However, today it's just a matter of cut-n-paste of code I already have, so I may-as-well try to help.
Note - both approaches display the image, only the second makes it available for saving.

JavaScript

<!DOCTYPE html>
<html>
<head>
<script>
function newEl(tag){return document.createElement(tag);}

window.addEventListener('load', mInit, false);

// rbgData - 3 bytes per pixel - alpha-channel data not used (or valid)
//
function createImageFromRGBdata(rgbData, width, height)
{
	var mCanvas = newEl('canvas');
	mCanvas.width = width;
	mCanvas.height = height;
	
	var mContext = mCanvas.getContext('2d');
	var mImgData = mContext.createImageData(width, height);
	
	var srcIndex=0, dstIndex=0, curPixelNum=0;
	
	for (curPixelNum=0; curPixelNum<width*height;  curPixelNum++)
	{
		mImgData.data[dstIndex] = rgbData[srcIndex];		// r
		mImgData.data[dstIndex+1] = rgbData[srcIndex+1];	// g
		mImgData.data[dstIndex+2] = rgbData[srcIndex+2];	// b
		mImgData.data[dstIndex+3] = 255; // 255 = 0xFF - constant alpha, 100% opaque
		srcIndex += 3;
		dstIndex += 4;
	}
	mContext.putImageData(mImgData, 0, 0);
	return mCanvas;
}


var rgbData = new Array(
0xff,0xff,0xff,  0xff,0xff,0xff,  0xff,0xff,0xff,  0xff,0xff,0xff,// white,white,white, white
0xff,0xff,0xff,  0xff,0x00,0x00,  0x00,0xff,0x00,  0xff,0xff,0xff,// white,  red,green, white
0xff,0xff,0xff,  0x00,0x00,0xff,  0xff,0xff,0x00,  0xff,0xff,0xff,// white, blue,yellow,white
0xff,0xff,0xff,  0xff,0xff,0xff,  0xff,0xff,0xff,  0xff,0xff,0xff // white,white,white, white
);

function mInit()
{
	// 1. - append data as a canvas element
	var mCanvas = createImageFromRGBdata(rgbData, 4, 4);
	mCanvas.setAttribute('style', "width:64px; height:64px; border:solid 1px black"); // make it large enough to be visible
	document.body.appendChild( mCanvas );
	
	// 2 - append data as a (saveable) image
	var mImg = newEl("img");
	var imgDataUrl = mCanvas.toDataURL();	// make a base64 string of the image data (the array above)
	mImg.src = imgDataUrl;
	mImg.setAttribute('style', "width:64px; height:64px; border:solid 1px black"); // make it large enough to be visible
	document.body.appendChild(mImg);
}

</script>
<style>
</style>
</head>
<body>
</body>
</html>