Consider changing image for surface=pebblestone

[praszuk]

Recently, I noticed that 2 SC users used it incorrectly, where the objects are probably more like surface=compacted or surface=fine_gravel.

The current image looks more like surface=compacted instead of loosy, rounded stones.

Can we use the same image from the OSM wiki instead?

https://wiki.openstreetmap.org/wiki/Tag:surface%3Dpebblestone

StreetComplete/app/src/androidMain/res/authors.txt

Line 262 in d34857b

surface_pebblestone.jpg CC-BY-SA 2.0 https://wiki.openstreetmap.org/wiki/File:Dscf1829-800.jpg (FrankM)

[mnalis]

or this one with more irregular ones:
https://commons.wikimedia.org/wiki/File:Pebbles_Chesil_Beach_Portland.jpg

I think we should need to crop only a portion of the picture (so it is in size like "Coarse gravel"), because if it is just resized to small part of screen (as the current picture is) it is not going to be very detectable for what it is.

[westnordost]

We are using the picture from the wiki. It was changed just a few months ago to the current one (without a comment). And I don't think the now current picture is very good, it looks too clean, artificial. This suggests that pebblestone should only be tagged on such squeaky clean pebblestone surfaces. Pebblestone surfaces you'd maybe see when you look into one of the containers in a store that sells various gravel stones. This however would reduce the range of surfaces one would tag this value to by a lot, i.e. would be like a redefinition of this tag.

The old wiki picture does a much better job at showing a typical pebblestone surface in reality, in my opinion. I'd be fine with a picture that shows a bit more clearly the round pebblestones, i.e. is a bit further away from compacted and fine_gravel, but the suggested picture is clearly worse, too clean, artificial.

[mnalis]

The old wiki picture does a much better job at showing a typical pebblestone surface in reality, in my opinion. I'd be fine with a picture that shows a bit more clearly the round pebblestones

Did you not seem my suggestion with different picture in a comment above @westnordost, i.e. https://commons.wikimedia.org/wiki/File:Pebbles_Chesil_Beach_Portland.jpg ?

Or if even more irregulatiries is wanted, maybe https://commons.wikimedia.org/wiki/File:Pebbles_(63814349).jpeg ?

[westnordost]

Yes, I did. It looks very similar to the one suggested in this ticket.

My understanding of pebblestone surface is that it doesn't need to be composed of only loose pebblestones to be tagged as such since it is a natural surface, so it's always going to be some sort of mix and I want the picture to reflect that. The picture used by StreetComplete has been the picture in the wiki for at least 5 years on Tag:surface=pebblestone

Digging deeper, though, I notice that on Key:surface, the image of pebblestone has always been this somewhat squeaky clean picture of pebblestones.

So, to summarize, I'm fine with changing the current picture to show loose pebbles more clearly, but then it still has to be a picture that shows a clearly natural surface, see above.

For example this picture would tick all the boxes (lower right corner)

File:Shingle_beach_on_the_Grune_peninsula_-_geograph.org.uk_-_6960554.jpg, however, I think the resolution is too small. I.e. in the thumbnail, the pebblestones would be so small that they wouldn't be easily identifiable as such.

See?

Some others which initially looked good but are not ideal:

• https://commons.wikimedia.org/wiki/File:Shingle_beach_with_parking_-_geograph.org.uk_-_4996931.jpg (lower right corner) blurry at high resolution, i.e. pebblestones would probably end up too small in thumbnail
• https://commons.wikimedia.org/wiki/File:Shingle_Beach_and_Groyne_at_Worthing.JPG might be too much contrast (light/shadow) due to the setting sun, might also end up too small in thumbnail
• https://commons.wikimedia.org/wiki/File:Boulders_and_shingle_on_Aber_Rhigian_Beach_-_geograph.org.uk_-_7859065.jpg or https://commons.wikimedia.org/wiki/File:Shingle_beach_at_Morfa_Dinlle_-_geograph.org.uk_-_7644488.jpg too clean - no mixture of materials at all
• https://commons.wikimedia.org/wiki/File:Sand_and_shingle_at_Cooden_Beach_-_geograph.org.uk_-_4997344.jpg (lower right corner) this again might be too little pebblestone, i.e. it is somewhat similar to the current picture

[mnalis]

So, to summarize, I'm fine with changing the current picture to show loose pebbles more clearly, but then it still has to be a picture that shows a clearly natural surface, see above.

Hm, ok. But those two examples of yours of "too clean - no mixture of materials at all" seem natural enough for me - no designer put those pebbles on those beaches. And we want some clarity (after all, that "coarse gravel" picture is also likely to dirtier in many situations in real world)... Would a crop of one of those would be fine?

While old wiki picture also had problems with:

• low resolution / blurry
• too washed out

my main complaint however about that original picture in SC is about its "zoom", i.e.

• pebbles are too small to be recognizable¹
• IMHO, the size of average pebble should be about the size of ones in "Unhewn pebblestone" and "Coarse gravel" to be recognizable.

So maybe something more like this quick mockup (original on the left vs. two examples)? :

Footnotes

1. when viewed on just a tiny part of small part of 6.5" mobile phone screen. Maybe if I used 15" tablet and same image was half of screen it would be just fine. ↩

[mnalis]

Those "dirty" pebbles look much less recognizable IMHO, e.g.

[matkoniecz]

So maybe something more like this quick mockup (original on the left vs. two examples)? 👍

the pebbles seem very very large here, maybe scaling them to make them smaller (zooming out) would work?

[mnalis]

the pebbles seem very very large here, maybe scaling them to make them smaller (zooming out) would work?

Well the whole idea was to make them larger as to be clearly visible in details; as they were originally so small to be completely unrecognizable as pebbles. I'd say those on pictures above are on par with "Unhewn pebblestone" and "Coarse gravel" in size, maybe slightly (10-15%-ish?) larger?

If I make them much smaller, they start looking unrecognizable again. This is for example IMHO borderline at best, and probably already too small to be recognizable. If you didn't know "pebbles" means, would you be able to discern from this screenshot what they are? Could you even see that they are round at this size?

[matkoniecz]

something in between would likely be better than either

[mnalis]

something in between would likely be better than either

maybe one of those? (crop from Aber Rhigian Beach resized to 40% and 30%)

[matkoniecz]

these seem work for me

what others think?

[westnordost]

I think it's good.