Huge size difference in photos depending on app taken with and tablet

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11-24-2021 07:29 AM
DougBrowning
MVP Notable Contributor

We have one group who has a service that is way bigger than anyone else, even though there are less photos in it.

I think I traced it down to the 123 app vs the camera app.

Here the top photo was taken in 123 by hitting the Camera icon and taking it directly.  The bottom photo is the same exact shot but taken with the camera app.  It is less than half the size.

DougBrowning_0-1637767701603.png

 

What is going on here?  My guess is 123 is not allowing the iPad to do its normal compression and instead giving a non compressed photo?  Also the bummer is that even when reducing the image size using max-pixels the photos are still not really compressed and larger than the camera app.

iPad Pro 12 inch with a 12 MP camera and iOS 15.  Using Unrestricted in 123 settings.

Then it gets really weird.

Next I tested a iPhone 8+ and a iPhone mini and there is 0 diff in size.  

Next tested a iPad Pro 11 and 123 is then smaller than the camera app - I checked and it is iOS 14.7.  Tested a iPad regular 6th gen and the 123 app is half the size of the camera (so both the total opposite on the Pro 12) - this one is 14.8.  Then I tested a Pixel 4 and the camera app is 4x the size of 123 app. 

Next I had everyone update to iOS 15.  Made no difference. For some reason just my iPad Pro 12 inch is larger in 123.  No idea why.  Still seeing with the rest of them that the camera app is 2x the size of 123.  Still not sure why.  I did find some posts of this happening to iOS devices suddenly doing this. 

Anyone else see this or know what is going on here?  There are no settings for this kind of stuff in the iPad so I am at a total loss now as to what to advise the staff.

thanks a lot

 

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8 Replies
Philip-Wilson
Esri Notable Contributor

Hi @DougBrowning,

This is expected if you are using different devices with different cameras and also comparing the native camera app vs Survey123 camera app. Making the pixel size smaller will not change the jpeg compression, but the image file size should be smaller as there are less pixels, but the compression is still the same, so the difference may not be a big as you are thinking.

The Survey123 camera app uses a default jpeg compression when saving the image (75% compression). The pixel size of the image will be based on one of 3 things: the survey image setting size (pixels), or the max-pixels setting on a per image question basis, or in some cases the pixel size used is the maximum supported resolution of the camera closest to the set size (previous 2 options) or is the unlimited size which is the maximum supported resolution reported by the camera.

When using the native camera app the settings applied in that camera app or at the device OS level will be used, this may include image size, aspect ratio, file type, compression, and many other configurable options that can be applied to native camera app. Survey123 can not use the settings configured in the native camera app or at the OS settings level, the OS does not provide a way to read these settings and apply them to the internal Survey123 camera app.

There may be differences between iOS versions also using their native camera app, they update and change things with cameras each major update. Also depending on the actual camera sensor hardware, you get different results between different devices. There are many variables when comparing different devices, OS versions, camera settings, so it will be very hard to get all your images to be the exact same file size, if they are coming from a wide range of devices, OS versions and using different camera apps.

Regards,

Phil.

 

 

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DougBrowning
MVP Notable Contributor

Can I ask what camera settings you mean?  I did some research and it says there are no user settings on an iPad.  Can you let me know where you see this?  Only things I have are Formats High Efficiency vs Most compatible.  The High Eff seem smaller and are stored at 92 DPI and no resolution unit.  Most compatible is at 72 DPI and does have resolution note.  Most compatible is larger - almost double.

All of these were tested with totally unrestricted size settings.  

Next 123 is the one that is double the size here - sometimes that is.  

The iPad Pro 11 and 12 both use the exact same camera as far as I can tell.  So why the total flip flop?

Here is on my Pro 12 inch it is 96 DPI from the camera but 123 is 72 bit.  Yet is 2X the size from 123.  I see resolution unit in there in the 123 side but not camera.  Maybe a mismatch?

DougBrowning_0-1638300758313.png

 

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I could for sure see some diff but for some to be double the size is something I have not seen before.

Anyone else with ideas it is breaking our service and I do not know what to advise now.

thanks

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DougBrowning
MVP Notable Contributor

More testing and when I turn off the Live and HDR settings in the camera app the file gets another 1 MB bigger!  Now getting photos over 4 MB.  

Has anyone else tested this?  Thanks

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Philip-Wilson
Esri Notable Contributor

@DougBrowning do you mean the image after you attach it to the survey gets 1MB bigger, and was the original HEIC or JPEG taken with iOS camera? I would have thought turning off Live and HDR settings would make the image smaller as there is less additional image metadata stored with the original image.

Phil.

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Philip-Wilson
Esri Notable Contributor

Hi @DougBrowning ,

You are correct, on iOS there are not many camera settings. Under the Camera option in Settings app, there are a few options to change the format and preserve settings, as well as keep the normal photo if you are using HDR. When you open the camera app you can change the aspect ratio of the photo (photo, square, pano) and enable HDR. That is all the settings that iOS offer, wheras on Android there are a lot more.

The difference between "High Efficiency" vs "Most compatible" on iOS is the type of file that gets saved. "High Efficiency" are HEIC images, which are high quality and small file size. Wheras "Most compatible" are JPEG images. The newer HEIC images are not yet supported with AGO or Enterprise, so they can not be uploaded and attached to features in a feature layer.

Therefore in Survey123 we have to convert HEIC images back to JPEG when they are selected via the browse option, which will make the file size larger than original, but as the image has now been processed twice, may be smaller than the original JPEG image from the Survey123 camera. Even though the resolution and pixel density are the same, the HEIC format compresses the image data much more. If you take the photo with the native camera and save as most compatible, you should find the image file size to be closer, depending on the compression they use.

Note that when you use the inbuilt Survey123 camera, none of the settings selected above in the iOS Settings or camera app are used. The settings for Survey123 camera are all default inside the app, and the format of the Survey123 camera will always be JPEG at 75% compression.

Hope this helps.

Regards,

Phil.

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DougBrowning
MVP Notable Contributor

Thanks Phil now we may be hitting on something.

"The newer HEIC images are not yet supported with AGO or Enterprise, so they can not be uploaded and attached to features in a feature layer.

Therefore in Survey123 we have to convert HEIC images back to JPEG when they are selected via the browse option, which will make the file size larger than original, but as the image has now been processed twice"

This would make some sense that it would get weird.  But you also said "may be smaller than the original JPEG image from the Survey123 camera".  I am finding the opposite.  The 123 image is half the size of the image taken with the camera (well on every device except my iPad Pro 12 which I still cannot figure out why it is diff).  Could it be something with the 96 vs 72 DPI?  Or resolution unit?

On your other post  "do you mean the image after you attach it to the survey gets 1MB bigger, and was the original HEIC or JPEG taken with iOS camera? I would have thought turning off Live and HDR settings would make the image smaller as there is less additional image metadata stored with the original image"

Yep!  Makes no sense at all.  In this test 123 app was 1.3 MB, camera app then attach was 3.  Then turn off Live and HDR and its 4.3!  Just so weird.  Just tested with a diff iPad Pro 11 and same thing.  It is larger when these are turned off.  Could explain the pixel as well. I showed our National Mobile team yesterday and they are totally baffled as well.

I would try apple support but prob cannot get that high up to find out.

Looking like a resampling issue when attaching from a folder in 123?

Thanks a lot

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Philip-Wilson
Esri Notable Contributor

Hi Doug,

As discussed on our call earlier, can you please share the images, taken from different cameras and also attached, there shoudl be 5 examples:

1. HEIC image from iOS camera - original image from photo gallery.

2. JPEG image from iOS camera - original image from photo gallery.

3. HEIC image from iOS camera - attached to Survey123 via browse option and converted to JPEG.

4. JPEG image from iOS camera - attached to Survey123 via browse option as JPEG.

5. JPEG image captured with Survey123 in-built camera.

We will take a look at the images and metadata to see if there is any obvious explanation for the difference in file sizes after they are attached and submitted to the feature layer.

Regards,

Phil.

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DougBrowning
MVP Notable Contributor

Thanks as always Phil.  I did a ton of testing today but its not consistent enough to report yet.  Diff iPads and Androids are giving different results.  Also results are diff today then last test.

So far using the 123 built in app or attaching a HEIC setting on image via a folder seems to be the smallest.

One thing I did notice is that all images are 72 DPI no matter where they are taken.  Except when I have HEIC on and use the iPad camera, then attach via the folder icon the image is 96 DPI.  Even though the original copy from the tablet is 72.  No idea why but maybe it is a clue?  All other images I take and attach or look at are 72.

DougBrowning_0-1638571466507.png

iPad Pro 2020 12 inch numbers

DougBrowning_1-1638571683861.png

I am tracking down more iPads that were causing us issues and that is taking some time.

Thanks again