[WIP PATCH] Tile images so that we can zoom in to full resolution

[taylor.smock]

I'm using an undocumented Mapillary API for inspiration for this. I won't be using the API in the Mapillary plugin (yet -- I'm going to ask them if they can make the API documented and public, specifically for 360 images). Undocumented api looks like this: /<image_id>/tiles?z=<zoom>&fields=url,z,x,y.

Example responses:

• Image 514627522880380

  {"width":3840,"height":2160,"id":"514627522880380"}
  

  {
    "data": [
      {
        "url": "https://example.com",
        "z": 11,
        "x": 0,
        "y": 0
      },
      {
        "url": "https://example.com",
        "z": 11,
        "x": 1,
        "y": 0
      },
      {
        "url": "https://example.com",
        "z": 11,
        "x": 0,
        "y": 1
      },
      {
        "url": "https://example.com",
        "z": 11,
        "x": 1,
        "y": 1
      }
    ]
  }
  
  

  {
    "data": [
      {
        "url": "https://example.com",
        "z": 12,
        "x": 0,
        "y": 0
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 1,
        "y": 0
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 2,
        "y": 0
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 3,
        "y": 0
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 0,
        "y": 1
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 1,
        "y": 1
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 2,
        "y": 1
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 3,
        "y": 1
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 0,
        "y": 2
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 1,
        "y": 2
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 2,
        "y": 2
      },
      {
        "url": "https://example.com",
        "z": 12,
        "x": 3,
        "y": 2
      }
    ]
  }
  

The returned images are 1024x1024, except for those on the bottom/left edges.

At zoom 11, we have a 1x1 return, with a maximum size of 1024x1024.

(0, 1) and (1, 1) is 1024 × 64.
This indicates that the height for the tiled images is 1024 + 64, or 1088.

At zoom 12, we have a 4x3 return, with a maximum size of 4096x3072 (width x height). This is "full resolution".
(3, 2) is 768 × 112.

From this, we see that the maximum size doubles between z11 and z12. Conveniently, 2^zoom == max size (2¹¹ = 2048, 2¹² = 4096).

For JOSM internal use, we might want to use 256x256 (I think the imagery tiles use that).

[taylor.smock]

Fixes pan/zoom -- zoom does not currently zoom to the appropriate location. Panning works, but is somewhat jerky (image tiles are currently loaded in EDT, I'm looking into reusing JCSCachedTileLoader and related classes).

[skyper]

Replying to taylor.smock:

For JOSM internal use, we might want to use 256x256 (I think the imagery tiles use that).

I thought there have been some changes and it can also be 512x512.

[taylor.smock]

Load tiles in non-EDT thread. Still kind of jerky, but a lot better. Zoom still broken.

[taylor.smock]

Zoom fixed, panning broken for non-tiled images (panoramic images not yet checked)

[Don-vip]

Good start, thanks :) I think zoom works fine now even for panos (it's difficult to be sure without being able to pan).

[taylor.smock]

Replying to Don-vip:

Good start, thanks :) I think zoom works fine now even for panos (it's difficult to be sure without being able to pan).

I haven't touched the pano code yet for this patch.
Also explicitly not supported: non-default exif orientations. I'm currently disabling tiling since I *think* I will need to do a bunch of math to convert the tiles to the "right" coordinates (isTilingEnabled returns false if there is an orientation change due to exif).

But I was specifically looking at any classes that implemented IImageEntry but not IImageTiling. Right now, the only one I know of is in the Mapillary plugin. I can modify it fairly easily to be tiled, but at that point the Image Viewer would require all image classes to be tiled (not necessarily a bad thing). As of right now, almost all of the business logic is in IImageTiling, so it should be trivially easy for a developer to implement.

Current non-default methods in IImageTiling:

• getTileImage(int, int, int, int) (this is what actually gets the tile image, which is then cached)
• getDeepTileSet() (A tile cache, essentially. Very similar to that used for Imagery layers.)
• getHeight() (the full height of the image)
• getWidth() (the full width of the image)

[Don-vip]

Milestone renamed

[stoecker]

Milestone renamed

[taylor.smock]

Ticket #22060 has been marked as a duplicate of this ticket.

[stoecker]

Milestone renamed

[taylor.smock]

This might allow us to close #15574.

[taylor.smock]

Ticket #23162 has been marked as a duplicate of this ticket.

[StephaneP]

Replying to taylor.smock:

I've got a patch that worked for traditional images, but wasn't for spherical (360) images, which is why I haven't merged it. I should probably go back and see if I can figure out how to make it work with 360 images.

Perhaps you could take a look to this plugin. It can display spherical images with full resolution, but there are some problems with the orientation and the max zoom level :
​https://github.com/GhostFoxSledgehammer/panoviewer-josm

[richlv]

Is that aspect of the Mapillary API still undocumented?

[taylor.smock]

AFAIK, it is still undocumented. I don't think it has changed recently.