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]

Re: Access to &lt;img&gt; pixels

* Tim Streater wrote in comp.lang.javas cript:

>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.
--
Björn Höhrmann · mailto:bjoern@h oehrmann.de · http://bjoern.hoehrmann.de
Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de
68309 Mannheim · PGP Pub. KeyID: 0xA4357E78 · http://www.websitedev.de/

[Tim Streater]

Re: Access to &lt;img&gt; pixels

In article
<1k1o34tl0men0o v9o4d0q6g4k6lk9 tfcv7@hive.bjoe rn.hoehrmann.de >,
Bjoern Hoehrmann <bjoern@hoehrma nn.dewrote:

* Tim Streater wrote in comp.lang.javas cript:

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.

Now this, might be just what the doctor ordered.

Thanks - I shall give that scheme a try!

[VK]

Re: Access to &lt;img&gt; pixels

On May 27, 5:13 pm, Tim Streater <tim.strea...@d ante.org.ukwrot e:

In article
<1k1o34tl0men0o v9o4d0q6g4k6lk9 tf...@hive.bjoe rn.hoehrmann.de >,
Bjoern Hoehrmann <bjo...@hoehrma nn.dewrote:
>
>
>

* Tim Streater wrote in comp.lang.javas cript:

>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.

>
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]

Re: Access to &lt;img&gt; pixels

In article
<c9b69aa3-9da3-4062-bf45-fd71841e9138@r6 6g2000hsg.googl egroups.com>,
VK <schools_ring@y ahoo.comwrote:

On May 27, 5:13 pm, Tim Streater <tim.strea...@d ante.org.ukwrot e:

In article
<1k1o34tl0men0o v9o4d0q6g4k6lk9 tf...@hive.bjoe rn.hoehrmann.de >,
Bjoern Hoehrmann <bjo...@hoehrma nn.dewrote:

* Tim Streater wrote in comp.lang.javas cript:
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-...-in-js.html.gz
does just that.

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.

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

[david.karr]

Re: Access to &lt;img&gt; pixels

On May 27, 6:00 am, Tim Streater <tim.strea...@d ante.org.ukwrot e:

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.