Access to <img> pixels

[Tim Streater]

If I create an image thus:

var myImg = new Image ();

I can then do the following:

myImg.src = "someimage.jpg";

But, I can't seem to find a way to manipulate the pixels of the image in
myImg (say, to invert each one).

Equally, if I have image data that I have read in from a database
record, I don't seem to find a way to stuff that directly into myImg.

Is this all actually the case or have I overlooked something?

 

[Bjoern Hoehrmann]

* Tim Streater wrote in comp.lang.javascript:

If I create an image thus:

var myImg = new Image ();

I can then do the following:

myImg.src = "someimage.jpg";

But, I can't seem to find a way to manipulate the pixels of the image in
myImg (say, to invert each one).

Equally, if I have image data that I have read in from a database
record, I don't seem to find a way to stuff that directly into myImg.

Is this all actually the case or have I overlooked something?

This is all actually the case, you might want to look at SVG or the
proposals around "<canvas>". You could also use the 'data' URL scheme
and manipulate the string to manipulate the pixels, as an example,
http://www.bjoernsworld.de/temp/gif-palette-animation-in-js.html.gz
does just that.

 

[Tim Streater]

* Tim Streater wrote in comp.lang.javascript:

This is all actually the case, you might want to look at SVG or the
proposals around "<canvas>". You could also use the 'data' URL scheme
and manipulate the string to manipulate the pixels, as an example,
http://www.bjoernsworld.de/temp/gif-palette-animation-in-js.html.gz
does just that.

Now this, might be just what the doctor ordered.

Thanks - I shall give that scheme a try!

 

[VK]

Now this, might be just what the doctor ordered.

Thanks - I shall give that scheme a try!

Being warned that neither of IE versions supports that so Web-wide the
solution will work only for 10-20% of your visitors depending on the
world region. Can be not important for an intranet solution but
important to know for an open project.

 

[Tim Streater]

Being warned that neither of IE versions supports that so Web-wide the
solution will work only for 10-20% of your visitors depending on the
world region. Can be not important for an intranet solution but
important to know for an open project.

Thanks for the heads-up. This would be for a closed user group so I may
have some flexibility.

 

[david.karr]

If I create an image thus:

var myImg = new Image ();

I can then do the following:

myImg.src = "someimage.jpg";

But, I can't seem to find a way to manipulate the pixels of the image in
myImg (say, to invert each one).

Equally, if I have image data that I have read in from a database
record, I don't seem to find a way to stuff that directly into myImg.

Is this all actually the case or have I overlooked something?

It seems like this is something you could achieve with a Java applet.