Very fast image merging possible?

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samueljon..

Very fast image merging possible?

in General Discussion • Other • 4 months ago

Hi,

I have four 1920 x 1080 PImage instances with alpha channel that I have to "blend" together at runtime on every frame.

You may be tempted to ask why - and I may be able to answer it but it could be a long explanation.

I thought about having a PImage and just "copy" the others into it on every frame. In Flash you can copy pixels from an image extremely fast. But it looks like copy() ignores the alpha channel. I have tried blend() and it is very slow.

Could a custom shader do this very fast??

Best,

Sammi

Replies(3)

PhiLho

Re: Very fast image merging possible?

4 months ago

You can use tint() with an alpha value.
I gave an example at https://forum.processing.org/topic/fade-images-in-and-out-running-on-an-rss-feed-2-6-2013
Not sure if it is fast enough for you, but worth trying.

You can also do computations on the pixels[] arrays, or use OpenGL to do the blending (I know somebody has done that, I don't know how).

amnon.owed

Re: Very fast image merging possible?

4 months ago

See the GLSL_TextureMix example on my GitHub.

Link: https://github.com/AmnonOwed/P5_CanTut_GeometryTexturesShaders

samueljon..

Re: Very fast image merging possible?

4 months ago

Thank you both. I will try your suggestions. Using GLSL is very interesting. I wonder if passing 3 big images to the shader on every draw() does not slow things down. I am very new to shaders so it will be a good practice.

Best,

Sammi

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