Why is iNat butchering my photo resolution?

I am trying to upload recent observations but when I get to the upload screen, the JPEG resolution is severely decreased, pixellated at times. I know iNat will shrink files that are too large but I have never had issues with this file size before and the quality of my previous observations (same camera, same file size) has been just fine. Is this a bug or am I missing something?

For example, here is a photo I uploaded last month:

And the same photo when I go to the upload screen now:

But, is it uploaded that way or just shows so at upload screen?

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Take a look at

It’s helpful if you can crop the photo more closely to the subject. iNaturalist resizes images, so while we can zoom in to try to see it closer, the image does lose some resolution. Cropping usually makes it easier to get an identification too.

While in your case, the photo already shows the subject of the identification only, it likely is bigger than the size limit (some 2000x2000 pixels, I read some where else), and thus gets resized, too.

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iNat doesn’t in norm resize photos that way, it shouldn’t become blurry, if uploader accepts photo, it’s already not that big, so resizing usually doesn’t create such weird pics.

It is uploaded that way.

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My example shows exact same file uploaded at different points in time. I was not having this problem a month ago. If I understand correctly, a file that is too large should be only be reduced to iNat’s maximum pixel limit. Not this much.

There are two issues here. The image size is reduced from 1804 x 1474 to 1762 x 1384. This should not happen with images below 2024 x 2024. This is possibly happening because of the method of uploading. (Screenshot).

The main issue here the final image is badly compressed. However, that is partly because of jpg compression and will not be solved until such time where the much better HEIF files are widely implemented.

Edit: I had a quick look at the original photo. The original photo size was 5472 x 3648 and is now saved on iNat as 2024 x 1365. So that is the reason. Any image above 2024 gets reduced in iNat. Images which are much wider than tall as in a landscape photo will be proportional reduced which means the number of pixels the upright will be so much less than 2024. If you want to increase the quality of your photo reduce the image with your own software to exactly 2024 x 2024 before uploading to iNat. Your image will be much better without that pixelating. In most cases it will not matter but it is significant with DSLR photos which are wider or images cropped as landscapes.


I upload photos of the same size and they’re not looking as bad when uploaded as op’s phooto, but they do take a lot in uploader to start look not blurry/pixelated. https://www.inaturalist.org/photos/179760768?size=original but also my files of 5472 x 3648 size are bigger than 20mb and uploader won’t take them.

Your photo of 5472 x 3648 is roughly 19.9mb, certainly not bigger than 20mb. Most photos if reduced by iNaturalist will be fine. The issue comes with landscape or portrait fotos, where one side is much bigger than the other. There are extreme landscape fotos where the ob cropped the top or the bottom, which make the image worse.The example of the Pelican is borderline, but the quality reduction is there, because of several factors mentioned. If you @rlhardin want to try re uploading the Pelican as an exact square of 2024 x 2024 image the image would be significantly better. Also the upload speed would be significantly faster.

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You didn’t fully understand what I meant, my photo of that size (op photo size) is bigger than 20mb, I only can show you the smaller one which is little bit smaller than 20mb and can be uploaded to website. And it’s not as blurry as op one. I can’t show you a bigger file on the website as it doesn’t fit, but I never once saw my files being as blurred on iNat, while I upload files at 100% size when they fit.
Op said that’s the same file uploaded at different times, it’s not a file issue.

it’s hard to tell for sure, but i suspect this thread probably is discussing the same thing as another thread: https://forum.inaturalist.org/t/photo-colour-balance-changed-when-uploaded/29223. (moderators may want to consolidate.)

No I do not understand. Unless your file is saved in a NEF (or RAW/ TIFF) format? The latter can be much more in file size. Your original image in is 3381 x 5071 which is 17mb. The new file size (The “original”) which is ingenious by iNaturalist is now reduced to a 1365 x 2024 image (Portrait).

This “original size” in the label is wrong and should be changed.

This is a different issue. That has to do with JPG compression.

It’s just a example of how big files in norm are not getting super blurry, again, I can’t add a file of the size of op photo to iNat, as my files are more than 20mb when they’re at the same resolution as op’s photo, but even if I find one the closest to their one, it won’t be so blurry, it’s really insane how bad the second pic looks.

just to put things in context, i’m fairly certain that the 2 images included in the original post are just hand-cropped screenshots of images. so, for example, even though that first image is 1804x1474, the actual source photo might be much bigger if you’re measuring by pixels on the 100% image. i would assume that original image is getting resized, and that the resulting image is probably subject to all the subtle changes that may occur with jpg manipulation, including quality loss and / or color space changes.

I did explain what is happening in my Edit.

ok. so then i’m not sure why you think the two threads cover different issues. the conclusion in both threads seems to be that to avoid image quality changes, the submitter should manually crop their photos before uploading to mitigate the changes caused by resizing photos.

Agree with @pisum here wrt the issues at hand.

One more possible issue at hand here is that I believe the two images submitted for comparison were cropped for comparison of detail. I tried to duplicate the process and found when I took the submitted online observation original size and cropped it to a comparable size, I actually had to stretch it to get it to the size of the second image that was shown by the original poster - this further distorts the quality of the image. Maybe I’m missing something but that is the result I got.

Personally for speed of upload I tend to crop in close and submit my file size with a max of 1200 x 1200 and feel my images are fine and I retain a larger file size for future print purposes - 2048 x 2048 pixels is the max resize limit of the system. https://forum.inaturalist.org/t/notify-user-when-new-observation-matches-time-stamp-of-pre-existing-observation/253/10

@ tiwane stated: If it is larger than 2048 x 2048 pixels, it is resized so that its longest edge will be no longer than 2048 pixels. On mobile devices this is done before an image is uploaded (to save on data use) and on the web, this is done after the image is uploaded.

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I’ve been seeing the opposite effect. Most of my observations appear in higher resolution, especially on tablets.

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