 |
Author |
Topic: alpha()? (Read 249 times) |
|
madmerv
Guest
|
alpha()?
« on: Dec 18th, 2003, 4:01pm » |
|
Hey -- is there an alpha() function in proce55ing that is undocumented?
|
|
|
|
|
toxi
|
Re: alpha()?
« Reply #1 on: Dec 18th, 2003, 7:57pm » |
|
alpha() is a (still) undocumented method of the BImage object to set the alpha channel of an image. a very basic demo of it is here:
http://www.toxi.co.uk/p5/imagePatterns/
note, that all the syntax is not yet finalised and undocumented. source should work with rev.66 or newer...
now, back into lurker mode... 
|
http://toxi.co.uk/
|
|
|
michael05
|
Re: alpha()?
« Reply #2 on: Dec 25th, 2003, 9:30pm » |
|
hi
isn t there a more simple way to use alpha channels?
i tried to mask an image this way:
--------
lego = loadImage("lego.jpg");
legoAlpha = new BImage (lego.pixels, lego.width, lego.height, ALPHA);
legoAlpha.format = ALPHA;
for (int i=0; i<lego.pixels.length-1; i++)
{
if (red(lego.pixels[i]) < 5)
{
legoAlpha.pixels[i] = 255;
}
}
lego.alpha(legoAlpha);
hintergrund = loadImage("hintergrund.jpg");
background(hintergrund);
image(lego, 0, 0);
image(legoAlpha, 0, 0);
it does not really work. the unmasked park shows up distorted. when i uncomment "image(legoAlpha, 0, 0);" only the mask is showing up.
|
°°°°°°°°°°°°°°°°°°°°
http://www.m05.de
|
|
|
toxi
|
Re: alpha()?
« Reply #3 on: Dec 29th, 2003, 12:34pm » |
|
okay, in this case that means the latest version of the BImage class was not yet in CVS when rev67 was built. you can manually fix the format of the "lego" image by inserting the following line after calling the alpha() function:
lego.format=RGBA;
but again, this is only a temporarily needed fix for a still undocumented function
|
http://toxi.co.uk/
|
|
|
|
