How do I blend out to white? - Printable Version

How do I blend out to white? - Printable Version

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How do I blend out to white? - enginestar - 02-26-2018

Can someone tell me how I blend out to white?

Problem: I've learned how to adjust colour levels and make the background become white.
This is perfect... except most of the time, around the edges... there are bits of grey. These show when the placed on a pure white background.

Is there some way of making sure the edges of the background is pure white?
I was thinking of a gradient blend somehow?

ELSE... am I doing something wrong in the first place...?

Thanks.

RE: How do I blend out to white? - Blighty - 02-26-2018

Difficult to say from your description. What are you starting with and what is the desired end result. Can you post a sample image?

I suspect that the solution is not to make edges pure white, but to use Colour to Alpha to retain the anti-aliasing pixels. But I would like to see the sample image first.

RE: How do I blend out to white? - Espermaschine - 02-26-2018

Are you trying to make a mask ?

If only the edges are not white, why not make them white with a brush ?

RE: How do I blend out to white? - enginestar - 02-27-2018

thanks for the replies guys.

see this image:

[Image: whxXSu.jpg]

i saw a youtube video... it showed to use colors -> adjust levels and choose white and then click on an empty area.
it's awesome. i get all white background.

The problem i have is that i have images i took pics of in an image box. somehow, i have like a shadow effect on the outside.
i dont want the shadow effect - i just want pure white.

sometimes, it's REALLY subtle and only shows up when i put on a white background!

i dont want to just brush out - i would rather have blend in (hope that makes sense!)

let me know what you think.

thanks.

RE: How do I blend out to white? - Espermaschine - 02-27-2018

Im still not clear on what the goal is.

Do you want to remove the background and the shadow the object is casting, or do you want the background as white as possible ?

For the latter, you could crop the image, so that only the object remains, make the background as white as possible and replace the cropped bits with a white layer.
The technique with the Levels tool and the inbuild colourpickers, thats just defining a white point. Its not really a magic trick to make things white, because sometimes you need to tweak the Levels in a more delicate way (including the middle slider) to not loose the antialiasing or not affect the object you are trying to isolate.

What you are doing is retouching an image.
There is more involved than simply clicking a button.
Painting, cloning, blending modes, healing, content aware filling, masking - all these methods could be used, depending on the image.

For case one (getting rid of the cast shadows), i guess you need to take a photo with better lighting.

RE: How do I blend out to white? - Ofnuts - 02-28-2018

* use levels/curves to blow out the white to true white
* Colors>Color to alpha and remove the white, some blueish shadow is left
* Layer>Mask add layer mask, and init to "Transfer layer alpha channel"
* use levels/curves to make about everything below 140 completely black

[attachment=1492]

RE: How do I blend out to white? - enginestar - 02-28-2018

thanks for the replies
@Espermaschine - yes the second one is right. just want to get the background white

i'm doing my best with the pics.
i've got a lightbox.

@Ofnuts: that sounds really cool. a bit above my head.
could you point me to a few videos?

thanks.

RE: How do I blend out to white? - Ofnuts - 02-28-2018

(02-28-2018, 07:50 PM)enginestar Wrote: @Ofnuts: that sounds really cool. a bit above my head.
could you point me to a few videos?

I'll leave that to Rich Smile