Photography Asked on August 31, 2020
I’ve taken some stock photography of lots of clear bottles, and now want to remove the background (which is white-ish, because at a pinch I could leave it…) so that the bottle becomes transparent with highlighting.
My bottles are clear with different colored liquids with multiple refraction and reflection surfaces. I am looking for a background color subtraction effect that will allow me to get to transparent (hopefully with some sort of effect/opacity slider).
Ideas that I can’t pull off yet:
Notes for what doesn’t work (Photoshop terminology):
I’ll add more if I can remember what I’ve found
Gimp has a really nice 'Color to Alpha' feature that sounds like it does exactly what you want. It doesn't just erase one color, but tries to make things that are almost white into almost transparent. It's not perfect, but comes pretty close. Here's an example from the docs: 8.34. Color to Alpha…
Correct answer by Mark on August 31, 2020
This is what it sounds like to me that you are trying to do: You have taken a picture of transparent objects and would like to remove the background and preserve the transparency of the foreground objects (so that perhaps you could replace the background with something else).
First thing is a choice you have to make: You can use built in tools to do the job as quickly as possible, but you sacrifice a lot of quality and realism. Or you can put in a little time and do it manually but with far better results. I would choose the latter ;)
If I had to pull that off I would probably shoot a white background to start with, then in Photoshop (or the equivalent):
That would be my workflow. I would also probably stick a semi-transparent copy of the original image between the background and the clipped image as a reference for the brush and then get rid of it later. If you want a perfect background replacement though, you are going to need to do a little touch up depending on what the background is to make reflections and diffractions look realistic. Best of luck!
Answered by Jay on August 31, 2020
I have an idea
shoot the bottle once with a black background, exposing for the highlights, then with a white background, exposing for the shadows.
Pull the two images into a new document with a transparent background, applying the darken or multiply blend mode to the white background pic, and lighten or screen to the dark background pic.
Of course I haven't tried this in practice, but might have to after work!
Answered by Nick on August 31, 2020
I can't believe - I figured it out! (I am just a photoshop hacker)
So heres what will get you 80% of the way to a perfect transparency (higher numbers are on the top):
If someone would like to use this to make a tutorial (with images etc), feel free (I may even get to it one day) as long as you reference this answer in your tutorial and put a link in the comments below.
Answered by Stephen on August 31, 2020
Get help from others!
Recent Answers
Recent Questions
© 2024 TransWikia.com. All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP