I took a look at this a few weeks ago. I believe it's because people are trying to load pictures from their phone or camera in formats not expressly supported by the image server.

Many phones use a non-standard image format, for example my iPhone uses a format called HEIC, and if you try to load this direct into tm-img there is a risk that the file won't get processed in a predictable manner.

tm-img expects images in .bmp, .jpg, .jpeg, .bmp, .png, .gif, .mp4, .mov, .webpage, and .webm and there don't appear to be any additional settings for stuff like HEIC.

Here's the text of an email I sent to Graham and Keith on the matter:

Originally Posted by Tim
it all seems to be a bit strange. If I upload Keith’s pic direct, it comes out squashed with an image size of 1440 x 1080. If I import it into my photos app first (Mac Photos) and then export it before uploading, it comes out correctly with an image size of 721 x 1080, which is what it should be. We also know that if Keith does any editing on the pic, like cropping it, It comes out fine.

But if I do the same process with Graham’s pic it still appears squashed with an image size of 721 x 1080 but the picture is cropped. Importing it into Mac photos and then exporting before uploading gives a correct result with an image size of 721 x 1080 but not distortion and no cropping.

So, what can I conclude?

My hypothesis is that some cameras, regardless of picture format, do not always store the image in a ’typical’ format that the image server expects. We also know that this is not specific to camera type or operating system type or indeed specific camera, as sometimes the pictures upload fine and sometimes they don’t. As to why this is we can only speculate.

But it seems that doing any further processing in an application and then saving the image does appear to restore the picture information to a format that the image server processes correctly.

The recommendation therefore is:

1. Before uploading your pic to the server, get it into your photo library software and then save it to a temp location (I use my desktop) and then upload from there. This is my approach and I have never experienced any image distortion issues.

Or

2. If you want to do everything on your phone, make a minor edit to the picture first before uploading.

Hope this helps

Tim H.
1986 4/4 VVTi Sport, 2002 LR Defender, 2022 Mini Cooper SE