erase white paper then fix?

[uncle808us]

Sometimes I want to erase a white background so I use filter/color/erase white paper but sometimes the makes certain parts of the image transparent (white stuff grey stuff etc) how can I repair these sections? Thanks

Hope this question is clear enough .

[anon1]

1 you can duplicate the layer before doing the "erase white paper" filter

2 apply the "erase white paper" on the bottom image

3a add a mask to the top image, invert mask

4a paint white on the mask in the areas you want to bring back

 

or 

3b use blend ranges of the top image, go to "source layer range" and adjust the right side downwards so that the bright parts are not opaque, you can also use this and masks in conjunction

 

here is how you use blend if/ blend ranges

https://forum.affinity.serif.com/index.php?/topic/17364-blend-if-blend-ranges/?p=79182

 

or just use blend if of one single layer in first place so that white gets transparent, you can then adjust the graduation yourself instead of using the fixed erase white paper filter

I wonder what "erase white paper" does apart from a sort of blend ranges thing anyway?

 

hope that helps  :)

[JimmyJack]

Erase White Paper should really be called Erase "L" Value.... which is what it does (AFAI can tell).

If you want it to use it to actually "erase white paper", it should only be applied on purely black and white imagery.

Otherwise it'll give you levels of transparency :o .

[MEB]

Hi uncle808us

The Erase White Filter is indeed intended to be used to literally "erase white paper" from scanned drawings. Although you can use it for other purposes (including colour images) it wasn't designed for that purpose.

 

If you create a selection of the subject you want unaffected by the filter, invert it and shrink as needed, you can use then it to remove the white from colour images too.