Denotations of the Live Filters "Schatten vergrößern" und "Lichter vergrößern" are interchanged

[iconoclast]

Hello!

Some minutes ago I noticed that the denotations of the Live Filters "Schatten vergrößern" (increase Shadows) and "Lichter vergrößern" (Increase Lights) are interchanged, at least in the german version of Affinity Photo. Both do exactly the opposite of what they promise. Not a big issue, but worth to be fixed some day, I think.

[NotMyFault]

Hi,

could you provide a screenshot (both languages) using the example document?

Does it affect live filter or destructive filter?

Use a black to white gradient as background,

and 3 lines with 0 / 50 / 100% gray color crossing the gradient.

on iPad, all languages seem correct (EN, DE)

maximize blur tester.afphoto

Edited April 7, 2022 by NotMyFault
Added sample doc

[iconoclast]

Hi NotMyFault!

Sorry, but as I tried to make a screenshot of this issue some minutes ago, everything worked as it should. Seems that it was only a temporary problem. I made several tests yesterday evening, and it was always as I described above. But today all seems to be okay. Weird!

[Dan C]

Hi @iconoclast & @NotMyFault,

From my testing, these filters appear to be working correctly - however I'm a little confused on the translation.

These filters should be 'Maximum Blur' and Minimum Blur', but the German names provided are referring to 'lights & shadows'. Is this the expected translation for these filters in your opinion, or does this need logging with our translation team?

Many thanks in advance!

[iconoclast]

Hi Dan!

In my understanding those two filters are not made for bluring. I know similar filters from GIMP, called "Erweitern" and "Erodieren". The first one increases light areas by adding light pixels and decreases the dark ones simultaneous. The other one does the opposite thing. But both without bluring. As far as I remember, Photoshop has something like that too. I think the two filters in Photo are made for the same tasks.

I made some additional tests, and my problem of yesterday evening may have had to do with the alpha channel. I'm not sure and will have to do some more tests, but the images I tested it with yesterday may possibly have been only black on transparency. That seems to behave different.

[Dan C]

Agreed, and thanks for the info regarding GIMP! The Minimum Blur (Schatten vergrößern) is designed to shrink highlights whilst broadening shadows, whilst the Maximum Blur (Lichter vergrößern) is designed to do the opposite.

Therefore, although not exact translations, I can better understand our choice of wording here - however I'm still going to raise this internally with our translation team to see if this is something we should update for clarity

[NotMyFault]

Giving a good name is really difficult. It definitely is technically a blur filter in my view, and it will enlarge areas with higher lightness values (or higher alpha).
 

The inverse effect could be a side effect if you deal with partially transparent layers. The affects the alpha channel, too. It then widens any area, even if the area itself is black, and the background is white.

So be careful about layer structure / nesting.

Unfortunately when used as nested filter on alpha, other bugs may play into the game.

[iconoclast]

2 minutes ago, NotMyFault said:

Giving a good name is really difficult. It definitely is technically a blur filter in my view, and it will enlarge areas with higher lightness values (or higher alpha).
 

The inverse effect could be a side effect if you deal with partially transparent layers. The affects the alpha channel, too. It then widens any area, even if the area itself is black, and the background is white.

So be careful about layer structure / nesting.

Unfortunately when used as nested filter on alpha, other bugs may play into the game.

Yes, it is not always easy to find the best name for an even simple function. I think the name of a filter or function should tell what it does, if possible. User friendly. This filters may somehow blur in a technical point of view, but to call it "Blur" is a little bit confusing, I think, because the effect doesn't look blurred. In my opinion, the german denotations fit very well to what they do.

But you are right concerning the behaviour of the filters with transparencies. It makes sense and I don't believe that it is a bug. You just have to remember that you need black and white for this filters, because they replace white pixels by black ones and vice versa. If there isn't black or white, it can't work as intended. Probably only a 1-Bit-Operation that can't handle any colour and alpha channels.

[NotMyFault]

19 minutes ago, iconoclast said:

f there isn't black or white, it can't work as intended. Probably only a 1-Bit-Operation that can't handle any colour and alpha channels.

I can’t follow the last sentence. My earlier post gives an example where it perfectly works with shades of grey.

[iconoclast]

29 minutes ago, NotMyFault said:

I can’t follow the last sentence. My earlier post gives an example where it perfectly works with shades of grey.

To be honest, I'm not really sure about this point. I don't really understand what I see, f.e. on my attached screenshots. It seems like pixels of each single grey value are replaced by pixels of the opposite grey value: 10% by 90%, 20% by 80%, 30% by 70% and so on. But it needs the hard difference between the values. Because in my example it affects only vertical. Is this what you meant?

My Test-Image:

The "Schatten vergrößern"-Filter applied to it:

The "Lichter vergrößern"-Filter applied to it:

 

[NotMyFault]

3 hours ago, iconoclast said:

It seems like pixels of each single grey value are replaced by pixels of the opposite grey value:

I  think a different interpretation better matches was is happening. 
The maximum blur filter takes the brightest color within the blur radius and applies it to all pixels within the radius. This is executed for every pixel individually.

 

Radius actually means a quadratic area (not circle).

To check, use an rectangle of 2 px over a darker background.

Maximum blur of 1 px increases the size to 4px (1 in every 4 directions).

 

[iconoclast]

1 hour ago, NotMyFault said:

I  think a different interpretation better matches was is happening. 
The maximum blur filter takes the brightest color within the blur radius and applies it to all pixels within the radius. This is executed for every pixel individually.

 

Radius actually means a quadratic area (not circle).

To check, use an rectangle of 2 px over a darker background.

Maximum blur of 1 px increases the size to 4px (1 in every 4 directions).

 

As I said, I'm not really sure about that. Funny thing, I know this kind of filters since I learned Photoshoping, so for about twenty years. I didn't use them very often, and I never asked myself what they are exactly doing and how. But you may be right, because the more you drag the sliders to the max, the more even complex curvy shapes become blocky structures. Filters that are for subtle use only. As the most filters are.