A new map metric: resolution-efficiency

[Milo]

Assuming my calculations are correct, the cylindrical projection with the same resolution efficiency as the Lambert cylindrical equal-area is given by

x = lambda
y = tan phi * sec phi

I checked it and it looks right to me.

and is even worse than the central cylindrical projection:

Makes sense, since the Lambert cylindrical equal-area projection has worse resolution-efficiency than the central cylindrical projection, given the same cutoff. And both are worse than Mercator.

However, if you choose the standard parallel that optimizes resolution-efficiency, instead of setting the standard parallel at the equator like Lambert does, then the optimal cylindrical equal-area projection has the same resolution-efficiency as the optimal central cylindrical projection (noting that the optimal standard parallel is different for each case - for the central cylindrical, the equator actually is optimal).

By the way, why do pictures now appear as links?

Probably an unintentional side effect of the recent forum update? Older posts still show the image, but new ones only show the link.

[PeteD]

However, if you choose the standard parallel that optimizes resolution-efficiency, instead of setting the standard parallel at the equator like Lambert does, then the optimal cylindrical equal-area projection has the same resolution-efficiency as the optimal central cylindrical projection (noting that the optimal standard parallel is different for each case - for the central cylindrical, the equator actually is optimal).

Interesting.

[daan]

By the way, why do pictures now appear as links?

Hm. That’s supposed to be fixed. See this

I’ll try to look into it tomorrow.

— daan

[daan]

I think you’ve merely exceeded the maximum in-line image size.

— daan

[PeteD]

Yes, that's solved it, but I had to get the image below 100 KiB for it to appear inline, whereas I've previously managed to post images over 300 KiB inline. Has the maximum inline image size been reduced?

[daan]

It’s actually the pixel dimensions, not the byte count. Maximum is set to 800x800. It’s sort of a concession to mobile devices. I can set it larger if people want that.

— daan

[Milo]

It’s actually the pixel dimensions, not the byte count. Maximum is set to 800x800. It’s sort of a concession to mobile devices. I can set it larger if people want that.

I recall that previously, images over the maximum size were rejected for upload entirely, rather than merely being link-only? Or am I misremembering?

If the board is going to have different behavior for images above a certain size, it would be a good idea for that size to actually be mentioned in the uploading form.