Mapillary: filter before download

[richlv]

There are cases where in an area with a huge number of Mapillary images I'm interested only in a small subset. For example, out of thousands of images I'd like to limit to the past month with a specific camera.

Currently the only way to do so seems to be download them all, filter afterwards.
This takes a long time, hits Mapillary infrastructure and seems to slow down JOSM considerably as well.
Would be wonderful if it was possible to apply filters beforehand, and only get the matching images/sequences downloaded.

[taylor.smock]

This is something I've thought about in the past.

The reason why I haven't done this is the following:

• I make the assumption that a user will want to modify filters later
• I also assume that a user may have an intermittent connection, so I want to avoid downloading as much as possible. Images are loaded on-demand (partially), but can be pre-cached.
• Every filter change would require re-downloading the images, some of which would be duplicates (depending upon how often filters are changed, this could be worse on the Mapillary servers). For example, lets say you filter for high quality images, (image_quality=5), and see that there are too few images. You then reduce the level to say image_quality=4. This is another request. Maybe there are still too few images, so you reduce it yet again to image_quality=3, and at that point, you feel that there is enough images for whatever you are doing. That is three requests (one per change).

All that being said, I've tried to make JOSM faster with large numbers of Mapillary images (for example, I avoid drawing individual images at low zoom levels), but it still is a somewhat jerky experience.

[richlv]

Yeah, repeated downloads would be a concern.
As time goes by, partial download usecases could be more useful, though - let's say there's a street that gets new images every few months. Several years later new images are uploaded, and getting to them would require downloading also all the historical info.
That's similar to my usecase, where in some area I needed only images less than a few weeks old, and filtered for a particular camera make, too.

[taylor.smock]

OK.

That makes sense.

Initially, if I get around to implementing this, I'll probably only filter based off of start year increments to give some balance between requesting too much and requesting too little. (so 0-0.99 years becomes 1 year, 1.0-1.99 becomes 2 years, etc.).

[taylor.smock]

​https://blog.mapillary.com/update/2021/03/03/preparing-for-the-new-mapillary-api.html

A more appropriate resolution would be cantfix, as the new API endpoints will not have filtering capabilities.