Remove White on Picture

[Sirenix]

Hey Guys with which tool i can Remove white Background for a PNG?

 

The Ereaser is not good it remove all

[Callum]

Hi Sirenix,

 

Welcome to the Forums :)

 

I would recommend trying the Erase White Paper filter you can access it by going to , Filters -> Colour -> Erase White Paper.

 

C

[Sirenix]

last time it was under the remover in the test version

[Sirenix]

i don't find this filter

[MEB]

Hi Sirenix,

Welcome to Affinity Forums :)

Filters are only available in Affinity Photo. If you are using it go to menu Filters ▸ Colour ▸ Erase White Paper.

[R C-R]

Callum, MEB, et all:

 

According to Affinity Photo Help, "The Erase White Paper filter applies transparency to white areas of an image to remove them. All other colours remain unaffected."

 

However, I have never been able to get it to work as described. Instead, everything that is lighter than some threshold lightness value is affected, turning it partially transparent. See below for one example. In it, the jukebox png file has been placed over a blue fill layer, & then the filter applied. Note that in the "After" version almost everything that isn't pure black has been turned partially transparent, allowing the blue fill to show through.

Am I doing something wrong or is this a bug or what?

[MEB]

The purpose of the filter is to remove the white background from a document. Have you tried it with an image with a white background?

I don't believe it's intended for another application/use other than this.

[R C-R]

The purpose of the filter is to remove the white background from a document. Have you tried it with an image with a white background?

Yes, & I get the same results. Very white shades are removed completely (including those within a colored foreground object), but all light colored areas become partially transparent, even those that contain saturated colors. The filter only works cleanly on images like the one in the help topic in which every pixel is either black or white.

 

This even applies to greyscale images. The attached afphoto document is a single layer Greyscale (8 bit) color format one with four sections, at 0%, 25%, 50&, & 100% black. This labeled screenshot shows what happens before & after I apply the Erase White Paper filter to it:

4 greys Erase White test.afphoto

[MEB]

I believe that's expected. It's the only way to get smooth transitions to transparent around the boundaries of the objects (the jagged areas) so they can be easily blended with a different background. If you want to protect specific areas from being affected in your image, you can create a selection before applying the filter.

Obviously this will all look out of place in a "synthetic" test like in your example.

[Madame]

Although it's just intended to erase white background I used it with great luck to remove a blown out sky.

 

I was out photographing a dark building, and didn't bring a tripod. I took a second picture and exposed for sky near by -without the building.

(This I used as a background layer)

There was foliage in the picture of the building, but it worked perfectly.

[MEB]

There's nothing stopping you from using the tools creatively :)

Sometimes it's the best way to get interesting results.

[evtonic3]

Yes I always thought that Hey this is great for purchased stock photos! And it is. I would suggest to those that are pushing this simple filter to do other than that is to make a duplicate first then apply the filter to the bottom one and add in on top (with a blank layer mask) what you didn't want touched. 

[R C-R]

I believe that's expected.

My point is that it is not at all what one would expect from what the help topic says about the filter affecting only white areas & all other colors being unaffected. As you can see from my examples (& I suspect from the creative way Madame said she used the filter) that very obviously is not all it does.

 

I have experimented not only with synthetic test images but also with a wide variety of "natural" images, including stock photos of objects shot against a white background, monochrome photos, under & over exposed photos, etc. The filter does not just turn pure white (0% black) areas transparent, it adds transparency to everything in the image that is not 100% black.

 

From what I can tell, the amount of transparency added is in some way proportional to grayscale level (which is what I was trying to show in my last screen shot), so the blacker a pixel is, the less transparency the filter applies to it. But even a pixel that is showing as 98% black in the Info panel set to display greyscale levels shows a very slight added transparency that is discernible if a brightly colored fill layer is placed behind that image layer.

[MEB]

The filter was developed to help you get rid of the white from line art, drawings etc (thus the name). If you limit the affected area with a selection you may also use it to remove the white background from photos etc (colour images), but it's not intended to be applied over a photography as a regular filter, so the results you're getting are not unexpected.

 

It may be used for other things creatively, but i don't believe we can find any logic for its results outside the context of its original purpose.

[R C-R]

MEB, I understand that but it still remains true that the description of the filter in Affinity Photo Help is misleading:

 

"The Erase White Paper filter applies transparency to white areas of an image to remove them. All other colours remain unaffected."

 

It does mention that it is "really" useful for scanned line art on physical media, but it just plain wrong when it says all other colors will remain unaffected.

[JimmyJack]

BUG!  ;)

[R C-R]

I don't know if it is a bug, at least in the sense of unintended behavior, but whatever the intent it does not do only what the help topic says it should do. This is unfortunate because that can cause a lot of confusion & wasted time trying to figure out why it doesn't work as described.

[Sirenix]

i just want remove white background from a picture in easy way but don't work like last time on affinity test.

 

on pixelmatr it works without problem

 

please help me to make png!

[JimmyJack]

This might work for you (it would help if we could see, at least a portion of, the image you're working with).

 

Use Magic Wand on a white section with the appropriate tolerance setting (with "Contiguous" checked if needed).

Because there is no antialiasing (bold face is directed at Affinity, not you) you have to "refine" the selection.

Go to Select > Refine Edges OR switch to Selection Brush Tool and hit Refine.

 

Once in the refine window don't do anything (well, maybe adjust the Ramp down a touch), just hit Apply. The selection should now be softer.

Hit delete.

 

----

 

@ RCR. Meant more in a tongue in cheek kinda way. Erase White Paper should work as advertised. Which is your point after all.

@ Affinity. Erase White Paper should actually be called "Erase L Value". Apart from a "creative" result, it only really works on all black artwork. (In that specific case it's a fantastic one click solution.)