Grayscaling just an image

Core Library Questions

jackoz

in Core Library Questions • 2 years ago

Hello, I'm using Processing intensively and never had a problem, I've always been able to find how to do what I needed to do but I'm unable to understand how to apply the filter function to just one blend.

What I need to achieve is that I have something like

// previous drawing
// then I blend just an image
Gfx.applet.blend(texture.img, sx, th*r, tw, th, tx, ty, tw, th, PApplet.BLEND);
// next drawing

I would like to make grayscale (by using filter(GRAY) ) just that image, but blindly calling it after the blend will make grayscale whatever is drawn before the image. Is there something easy I'm missing?

Thanks in advance

Replies(4)

PhiLho

Re: Grayscaling just an image

2 years ago

Put the image in a PGraphics, then apply the filter on it before displaying the image.

jackoz

Re: Grayscaling just an image

2 years ago

Ok, now I got how it works, thanks a lot.

But I guess that, since my drawing occurs in a loop and I just know at runtime if the grayscale is needed or not, it is better to instantiate a PGraphics once and use it just when needed (to avoid new object allocations on each repaint)..

Thanks a lot :)

jon.haber

Re: Grayscaling just an image

2 years ago

could you expand on this answer a bit, i have the same question and am still lost, how do i put a single image inside of a PGraphics?

PhiLho

Re: Grayscaling just an image

2 years ago

Just draw it on the PGraphics (using image() for example).

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