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Huffman coding for an image using javascript

I need to get the Huffman coding for the <img> in html, I have a JavaScript function that generates Huffman coding and it takes a string as input, so I need to convert the image in the <img> into a string somehow, get the Huffman coding and output it in the html.
My problem converting the <img> to a string, I've searched a lot but I still don't know how to proceed

You can use a canvas like this
How to get base64 encoded data from html image
Ultimately you need the image converted to base 64, Which can either be done server side or client side if supported
http://en.wikipedia.org/wiki/Data_URI_scheme
You can then huffman encode the base 64

Is there an HTML5 method for displaying a tiff image data already loaded into memory

I have a tiff image stored in memory (in a javascript variable). What is the javascript or html technique for displaying this image in the browser window? Is there a "drawimage" type of function?

Native browser-support for tiff files is still pretty bad.
Wikipedia has a nice overview on browsers Image format support.
That being said; since a .tiff image is still essentially a raster-image, one could indeed convert it (the tricky part is stuff like supporting different compression-algorithms like PACKBITS, DEFLATE, LZW, etc) to another (browser-supported) raster-format (so one could feed it as a data:img-source).
There is a library called Tiffus: a client side pure Javascript imaging library to load, save and manipulate binary images.
The original project aim was was to create a plain Javascript chrome extension which can convert single/multi page TIFF image/s to BMP/GIF image (this is where the name came from).
However now it supports:
Windows BMP (no compression, RLE)
OS/2 BMP
ICO
GIF
JPEG
PNG
TIFF
and currently supports the folloing image functions:
load
save
resize
flip
invert color
Basically it works like this:
Source image downloaded as Binary Data using XMLHttpRequest with
MimeType('text/plain; charset=x-user-defined'); (future: HTML5
Canvas ImageData)
Imageprocessing using Tiffus
Desination image shown as Data URI scheme (future: HTML5 Canvas ImageData)
Note that according to the above; the author expects to use HTML5 Canvas ImageData in the future.
Hope this helps!

Data uri's - base 64 encoding. Can you do it automatic with a javascript?

I have a question about base64 encoding for images. I used base64 for small background images. I convert it with a online base64 tool. And put it directly in the CSS file.
But is there a way. That the base64 encoding go automatic. When i upload the files to the server or when i run the website. Then the small background images in the CSS. Convert automatic to base64 encoding. Do you understand??
Thanks for help!

Well, I'm not sure if I exactly understand your question. However, the <canvas> element offers a function named .toDataURL()help, which converts the contents from the <canvas> node into a Base64 encoded string. But that does not make much sense in your case anyway I guess.
Same story for window.btoa(). You would need to ordinary transfer the images to the client and then converting them, which does not make any sense. So you would need a tool/script which runs on the server and transfers images as base64. And guess what, it exists.
supplyJS
Using supplyJS, you could create a call like
supply.listen('image/jpg', function(payload, filename) {
jQuery('<img>', {
src: 'data:image/jpeg;base64,' + payload
}).appendTo(document.body);
});
supply.setDealer('/cgi-bin/supply.pl').files({
images: [
'/images/foo.jpg',
'/images/bar.jpg',
'/images/another.jpg'
]
});
It will natively convert all images into base64 to transfer them.
Example: http://www.typeofnan.com/lab/mxhr-stream/

What's the purpose of this Javascript variable?

What does this do, and why is it declared this way?
var shroom = 'data:image/gif;base64,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%3D%3D';

It represents a GIF image encoded in base 64.

http://en.wikipedia.org/wiki/Data_URI_scheme

It's a Data URI, which is a file encoded in a URL. More info can be found on wikipedia. Here's an online tool used to create them:
http://software.hixie.ch/utilities/cgi/data/data
I believe IE doesn't have total support for Data URIs, so they're not too commonly used. If IE did, though, they'd be great for icons and small graphics embedded right into style sheets.

Here is a link to encode base 64 with Javascript
Base 64 with Javascript

Javascript Hex String to Image

I'll cut right to the chase. Right now I am developing a web based application. It has a PHP REST based architecture that serves up XML documents. On many of these documents attributes are hex encoded picture strings.
On the client side jQuery AJAX fetches an XML document with a picture in it. I need to display said picture in some <img> tags. However my knowledge on such methods is lacking so here I am asking for help.
Goal:
JavaScript String variable in hex or base64 >>> HTML displayed image.
Cross browser is required, or a hack for the ones that do not support it is fine.
Thanks,
Gunnar

Encode the images using base64 and write them out in a CDATA string into your XML with this format:
data:[<MIME-type>][;charset="<encoding>"][;base64],0123456789abcdefg...
When constructing your document, use this string as your src
<img src="data:image/png;base64,0123456789abcdefg..." />

Is it possible to use a php file just for rendering the image? That php file could write some base64 encoded values via
echo base64_decode($_GET['data']);
while you embed images like
<img src="http://host/yourPhpFileForDecode.php?data=base64encoded.../>