Exporting an image with background transparency?

Programming Questions

dehughes

Exporting an image with background transparency?

in Programming Questions • 3 years ago

Greetings,

I am working on a drawing application and I want to be able to export the drawings without any background. I haven't been able to figure this one out. Is this possible?

It's probably something trivial that I am missing.

Thanks!!

Darin

Replies(7)

partikelm..

Re: Exporting an image with background transparency?

3 years ago

try this
gifExport.setTransparent(0,0,0); // black is transparent

dehughes

Re: Re: Exporting an image with background transparency?

3 years ago

Thank you! Almost there. I didn't know gifAnimation library, but I've got it installed and I am successfully generating a GIF with tranparency. However, the drawings I am creating have a lot of black in them and that is getting filtered out as well.

Any suggestions?

dehughes

Re: Exporting an image with background transparency?

3 years ago

Ah...I am retarded. Got it now. Thank you!

PhiLho

Re: Exporting an image with background transparency?

3 years ago

I recommend to drop Gif in favor of PNG: no need for a library and that's a superior format.

To have transparency in the export, you have to draw on a PGrahics (in Java2D mode) and export that.

dehughes

Re: Re: Exporting an image with background transparency?

3 years ago

Thanks, I will give that a try.

I'm not too happy with the quality of the GIF image. Capturing the screen produces a much higher quality image but then I am stuck with the background.

Anyway, I greatly appreciate the input from both of you all.

Does there exist the concept of layers in Processing, such that each layer could be exported/rendered individually? I don't think I have fully gotten my head around some basic concepts.

I'm using ControlP5 for my slider controls right now but one thing I noticed was that I could no longer draw in the canvas when I was using ControlP5. I had to create a separate window for the GUI controls...which is fine, but not ideal for some applications.

PhiLho

Re: Exporting an image with background transparency?

3 years ago

I can't answer for controlP5 but I think people managed to mix drawings and controls. Make a separate topic in the contributed libraries section if you want (but I suggest first to do some searches, if not done already).

There is no layer concept in Processing, but you can create as many off-screen PGraphics with transparency as you want, then draw them in any order on the sketch's area, effectively simulating the layers.

amnon.owed

Re: Exporting an image with background transparency?

3 years ago

I'd second the use of PGraphics and PNG for your purpose. In fact, you could just use this sketch, which is like a 1-layer drawing program. Of course this can be easily extended to multiple layers. The advantage is also that they really act like 'layers' in the sense that one could move (re-position) the whole layer for example.

In addition, I would like to point out this library, which allows for layers in Processing. I haven't tried it myself, so can't say if it's any good. But perhaps it may be useful in this case.

Top Reply