Lighten major buildings fill and outline

[jeisenbe]

Related to #3071
Related to #2532
Related to #3589
Also see discussion in #3426

Changes proposed in this pull request:

• Lighten major-building-fill color: currently it is 20% darker than @building. With this PR it will be changed to 10% darker
• Lighten major-building-outline color: currently this is 25% darker than @major-building-fill. With this PR it will be changed to 15% darker.

Explanation:

• The dark major-building-fill color is fine for black icons, such as those used for place_of_worship, but it does not work will with brown, purple and orange icons
• The brown squares for building entrances are the same color as @building-outline, currently 15% darker than @building, so this is lighter than the major building color.
• The new color for major-buildings-fill is significantly lighter. Due to the way that darken works in the HSL color space, this also means that the color is less saturated and the hue is more similar to @building as well.
• With these changes, icons are better visible in train stations and airports. The one issue is places of worship are not as visible at z15 and z14, however this may be preferable.

Test rendering with links to the example places:

Hamburg Airport
https://www.openstreetmap.org/#map=17/53.63323/10.00529

• Also see the churches nearby on lower zoom levels
  z19 Before
  
  After
  

z17 Before

After

z15 Before

After

Hamburg train station and downtown churches
https://www.openstreetmap.org/#map=16/53.5477/10.0028

z18 Before

After

z16 Before

After

z14 Before

After

[jeisenbe]

New building colors:

LCH values:

Deltas between colors:

[kocio-pl]

What about proposed progressive major buildings color lightning? I don't remember the ticket where it was proposed.

[jeisenbe]

I thought there had been some previous discussion, but a search of all PRs and Issues for “major buildings” and “building color” didn’t find much. Do you mean that the color should change by zoom level?

…

On Mon, Jan 28, 2019 at 6:12 PM kocio-pl ***@***.***> wrote: What about proposed progressive major buildings color lightning? I don't remember the ticket where it was proposed. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#3659 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AoxshB4r3FKJ0cw6-9Q2jA2kyo74T1MJks5vHr8AgaJpZM4aVOEr> .

[kocio-pl]

Yes, exactly. Both ideas are OK for me, I have no clear preference, I just want to know what others think.

[jeisenbe]

Ok. I'm not sure if it is worth increasing the code complexity, but here is an example of what it could look like with a transition from z14 to 16:

z14 major-building-fill darkened 20% (same as master)

z15 major-building-fill darkened 15% (intermediate step)

z16 major-building-fill darkened 10% (same as this PR):

[imagico]

For better understanding of the color environment you are working in here - these are the medium lightness low chroma colors you have around:

http://davidjohnstone.net/pages/lch-lab-colour-gradient-picker#d9d0c9,d2c7bf,c8c8b5,cfcfcf,c4b6ab,b6b592,bbbbbb

In order: building, building-lowzoom, construction, place-of-worship, your major building idea, landfill, platform.

[jeisenbe]

I had compared this color to place_of_worship and landuse=construction, but I had not thought of landfill and platform. It looks like the delta to landfill is 13.8 - not huge, but enough. The delta to the current major-building-fill is 14.8 The delta to platform is now only 8.1 - but at high zoom levels where platforms are visible, the building outline will be shown, and this is much darker. Joseph

On Mon, Jan 28, 2019 at 8:44 PM Christoph Hormann : > For better understanding of the color environment you are working in

here - these are the medium lightness low chroma colors you have around: http://davidjohnstone.net/pages/lch-lab-colour-gradient-picker#d9d0c9,d2c7bf,c8c8b5,cfcfcf,c4b6ab,b6b592,bbbbbb In order: building, but building-lowzoom, construction, place-of-worship, *your major building idea*, landfill, platform

[imagico]

Well - i have not said the colors are indistinguishable - i just wanted you to be aware of the color context you are working in here.

By the way - i forgot the quarry color:

http://davidjohnstone.net/pages/lch-lab-colour-gradient-picker#d9d0c9,d2c7bf,c8c8b5,cfcfcf,c4b6ab,b6b592,bbbbbb,c5c3c3

Past discussion that might also be helpful: #2353, #2905, #2515.

[meased]

For reference, the original discussion was in #3426. Lightening of major buildings was originally a part of that PR, but the discussion focused mainly on minor buildings. The PR was renamed and merged with no visual changes, it only moved major/minor building selection from SQL to CSS.

[jragusa]

I agree with progressive major buildings colour lightning. Darken colour at low zoom emphasizes major building and lighten colour help to distinguish icon at high zoom.
It's off topic with regard to the PR, when looking to the colour panel provided by @imagico, I think that colour of landfill, construction and quarry could be unified.

[jeisenbe]

http://davidjohnstone.net/pages/lch-lab-colour-gradient-picker#d9d0c9,d2c7bf,c8c8b5,cfcfcf,c4b6ab,b6b592,bbbbbb,c5c3c3

According to the deltas based on Lab/LCH, the closest to the new buildings fill would be quarry, place_of_worship/religious landuse, and platform. All of these are neutral gray instead of brown, but the lightness levels are similar, especially for platform, though also for quarry.

New major-building-fill #c4b6ab vs @place_of_worship #d0d0d0: delta 11.7 (L8, c8)
New major-building #c4b6ab vs @quarry #c5c3c3: delta 8.6 (L4, c7)
New major-building #c4b6ab vs highway_platform #bbbbbb: delta 8.1 (L1, c8)

Looking at the test images from the train station at z16 and z18 above, the platforms look quite different from the major building color. In this case I think that the calculated delta underestimates the difference between neutral gray and brown, even though the lightness level is close.

Browns:
New major-building-fill #c4b6ab vs @construction #c7c7b4: delta 8.3 (L5, c2, h52)
New major-building-fill #c4b6ab vs @landfill #b6b592: delta 13.8 (L2, c11, h40)

The closest brown colors are landuse=construction/brownfield and landuse=landfill; the former is more likely to be found with buildings. This is probably the most difficult case. I'd consider this difference to be sufficiently large, if just barely.

@imagico has suggested combing the colors for quarry, landfill, construction (and brownfield), with #c5bea6 for all of these. This would be slightly closer than the current construction color:

New major-building-fill #c4b6ab vs alt-colors #c5bea6: delta 7.6 (L2, c5, h30)

Also, the delta between the current building-fill and the new major-building-fill would be Δ: 9.6 for comparison. But since this is mainly a difference in lightness, it's sufficiently visible on most computer screens.
New major-building-fill #c4b6ab vs building-fill #d9d0c9: delta 9.6 (L9, c3, h1)

I check the new major-building-line color, and it doesn't appear to be very close to any colors. The closest is the current building-line, unsurprisingly, followed by landfill.

New major-building-line #a48f7f vs building-line #b9a99d;: Δ 10 (L9, c4, h1)
New major-building-fill #a48f7f vs @landfill #b6b592: Δ: 17.5 (L12, c6, h42)

None of the icon colors is very close. The difference with @amenity-brown is delta 40.2 (improved from delta 32.8 with the current major-building-line), and @gastronomy-icon has delta 56.5 with the new outline color.

[jeisenbe]

Looking back at the discussion in #3426, here are some more examples:

Master:

Major buildings 10% darker (same as current commit)

Major buildings 15% darker (could be used at lower zoom levels?)

Hamburg station again, 15% darker major-buildings-fill:
z14 Master again

z14 - darker 15%

z15 - darker 15%

z16 - Master

z16 - darker 15%

z17 - darker 15%

z18 master

z18 - -darker 15%

[jeisenbe]

@meased in these test images -- #3426 (comment) -- what were the levels used at different zoom levels?

I'm guessing 20% (current) at z14 and 10% at high zoom, but not certain where you changed the levels.

[jeisenbe]

I've pushed a new commit that adds a major-building-low-zoom color for z14, which is 5% darker than the major-buildings-fill color (i.e. 15% darker than @building-fill). This matches the increased darkness of building-low-zoom, which is 4% darker than building-fill.

I also made some tests that would keep the current fill color at z14 (20% darker), with an intermediate color at z15 (15% darker) and then the proposed color at z16 and higher (10% darker).

Major-building on religious/place_of_worship color background:
https://www.openstreetmap.org/#map=17/53.57747/9.82394
z17 before

z17 after

z16 before

z16 after

z15 before

z15 after 10%

after 15%

z14 before / 20%

z14 15%

Major-building on landuse=construction
https://www.openstreetmap.org/#map=17/53.68447/9.99037
z17 before

z17 after

z16 before

z16 after

z15 before

z15 10%

z15 15%

z14 before / 20%

z14 15%

Major-building on graveyard/cemetery
https://www.openstreetmap.org/#map=17/53.6820/10.0479
z17 before

after

z16 before

after

z15 before

after 10%

15 percent

z14 before / 20%

z14 after 15%

Harburg train station
https://www.openstreetmap.org/#map=18/53.45665/9.99172
Before z18, z19

After

[jragusa]

#3647 convinces me to not support lighten colour at low zoom

[meased]

@meased in these test images -- #3426 (comment) -- what were the levels used at different zoom levels?

That was just a test that I never committed, but I believe it started with building-color at z17, then darkened it by a constant amount each zoom level (3% maybe?).

[jeisenbe]

Are others in favor of keeping the major buildings darker and more distinct at lower zoom levels?

Do the high zoom levels (z17, z18, z19) need to be darker, or is darken(@building-fill, 10%) enough?

More tests near the equator, in Yogyakarta, Indonesia:

Yogyakarta Airport:
https://www.openstreetmap.org/#map=16/-7.7855/110.4273
z16 before

z16 current commit - 10 percent

z16 - 15 percent darker and slightly stronger line color

z15 before

z15 current commit - 10 percent

z15 - 15 percent

z15 - 15 percent, darker line

z14 before

z14 current commit - 15 percent

National University, Yogyakarta
https://www.openstreetmap.org/#map=15/-7.7735/110.3966
z14 before

z14 current commit - 15 percent

z15 before

z15 current commit - 10 percent

z15 - 15 percent

z16 before

z16 current commit - 10 percent

z16 - 15 percent, darker line

z17 before

z17 current commit - 10 percent

z18 before

z18 current commit - 10 percent

[jeisenbe]

Singapore, Chiang Airport:

• Large airport terminals such as these are very visible, even after lightening the color and at low zoom levels near the equator, so they won't be a problem.

z18 Before

After 10%

z17 before

After 10%

z16

15%

10%

z15

15%

10%

z14 before

after 15%

Central Singapore

• There are at least 6 different types of place_of_worship here.
• It looks like the major-building-fill color doesn't need to be very dark at z16 and above, because the symbol is sufficient to highlight the location of the place_of_worship. But at z15 it's helpful to have a slightly darker fill color (15% instead of 10%) and line color.

z17 Chinatown before

After 10%

z17 Bugis, Before

after 10%

z16 Chinatown, before

15%

10%

z16 Bugis before

15%

10%

z15 before

15%

10%

[kocio-pl]

Are others in favor of keeping the major buildings darker and more distinct at lower zoom levels?

Yes, I would like to have them the same as in master. On z14 and z15 they are hard to notice and also look close to the construction when they are small.

Do the high zoom levels (z17, z18, z19) need to be darker, or is darken(@building-fill, 10%) enough?

I'm happy with high zoom appearance.

[jeisenbe]

OK, I've pushed a new commit to render major-buildings fill as darken(@building-fill: 20%) at z14 (same as the current rendering) and darken(@building-fill: 15%) at z15, as shown in the most recent test images.

Examples:
Major-building on religious/place_of_worship color background:
https://www.openstreetmap.org/#map=17/53.57747/9.82394
z17 after (10%)

z16 after (10%)

z15 after 15%

z14 (unchanged)

Singapore central city
z17 after 10%

z16 After 10%

z15 After 15%

[kocio-pl]

Thanks, that works for me too.

I hope now we can find some solution for minor (and underground) buildings too.

[danieldegroot2]

Whisper PR to #3641.