Problem with streaked vertical lines

[Tai Shimizu]

Sorry if I come across as a big Apple proponent, but I don't think Apple is entirely to blame for this mishap. Remember that Apple's primary customer base has little interest in or knowledge of photo quality, formats, etc. and are probably more concerned with disk space and photo sharing. So to be fair, I believe the onus should full on developers, particularly those of professional editing apps, to employ methods that preserve photo quality/integrity especially since many are available to them through iOS's extensive SDK.

So users should speak out and demand these improvements.

I agree, I wouldn't blame Apple for this at all; it seems to me the correct choice for them to make. In most circumstances the more heavily compressed image is superior for end users, especially on devices with such limited disc space. The onus is on developers of apps that require higher quality to ensure it.

 

[davideroccato]

@Tai Shimizu @Stackables
Just to add something, we had started a similar discussion in iPhoneArt time ago, then decided to write something in the Apple Forum as well where you can find here the discussion. At the end of that discussion I added a link to a bug reported in Open radar that involve UIImageJPEGRepresentation, that you can read here, and that might be interesting for you to know. I don't know if this is another method used in the process, or one of the possibility you can use for saving the pictures on the camera roll.

This link in OpenRadar explain exactly what's going on and it shouldn't happen because when an image is saved using a method the quality shouldn't change so much to take out green part from it and convert it in purple/magenta. Devs can use probably different method to acquire the same results but if they are not aware about that particular bug are not to blame as well, in my opinion.

@Mikeraboy @Stackables Thank you Sam for the clarification about Tiff, Png and jpg. So we understand it's not so easy for the users to know what to do if they don't run a few test for each app.

If I well understood, just talking about Tiff for example, to avoid too much confusion. Let's say an app have both editing and shooting characteristics. If that app saves in Tiff it doesn't automatically mean that it edits in Tiff when pictures are imported from the camera roll to the same app, or that it sends in Tiff with the "open in..." feature right? Probably yes but it's not sure 100%, the app could use different conversion methods for each area, or not?

 

[odilonvert]

FYI - I've shared the link on this discussion in whatever former IPA communities are out there (IPA Refugees, iPhoneart Studio Talk, iPhoneart Central). What makes MobiTog different and super valuable here is the active participation of developers - without that we'd all be flailing. !

 

[cortexcamera]

Hi everyone, I'm the developer of Cortex Camera and I just wanted to give my quick thoughts.

It's definitely a good idea to save in a lossless format if you're going to be editing the file and saving it again. Cortex Camera supports saving to PNG mainly for this use case.

When saving as JPG Cortex Camera uses the default quality setting. Based on the images posted to this thread, the default quality setting seems to have decreased in iOS 7. I agree that Apple is probably right to optimize for the most common case which is saving without the intention to edit. The color shifting seems more like a bug to me... I don't know that B&W images should become purple even with a low quality setting.

At any rate I will be paying a lot more attention to JPG encoding in Cortex Camera as a result of this thread.

 

[Mickey]

Sacha,

I am guessing that this was originally under-exposed and that you brought up the levels during your edit?

What I am seeing here could be vertical-banding which is fairly commonly seen in under-exposed digital captures that have had their levels raised in editing. An iPhone's sensor does not have a tremendous amount of dynamic range.

Could you post the original capture as a comparison?

Perfectly clear on the iPhone has a button to select to get rid of purple. It's not on their iPad version.
As far as the purple introduced during shooting with some bright light coming into the edge of the photo it happens with my high end Sony RX 100 as well. Maybe the sensor in digital cameras is also an issue.
I am not familiar with my B&W having purple issues.

 

[odilonvert]

but that still doesn't address why there is no purple problem with earlier phones and iOS - it has to be a hardware and/or software issue.

For non-mobile, non-point & shoot cameras you can use those hoods that block out peripheral light.

 

[Venomator]

Hi everyone, I'm the developer of Cortex Camera and I just wanted to give my quick thoughts.

It's definitely a good idea to save in a lossless format if you're going to be editing the file and saving it again. Cortex Camera supports saving to PNG mainly for this use case.

When saving as JPG Cortex Camera uses the default quality setting. Based on the images posted to this thread, the default quality setting seems to have decreased in iOS 7. I agree that Apple is probably right to optimize for the most common case which is saving without the intention to edit. The color shifting seems more like a bug to me... I don't know that B&W images should become purple even with a low quality setting.

At any rate I will be paying a lot more attention to JPG encoding in Cortex Camera as a result of this thread.

@cortexcamera - Hi Kevin and welcome to MobiTog.com, the happening place for Mobile Photography stuff around the planet!...

It is great you have picked up on the invite, bitten the bullet and decided to join this gritty discussion, we really do appreciate busy Developers taking time out to share their invaluable knowledge and experience with us mere mortals, thank you sir...

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[Stackables]

@Tai Shimizu @Stackables
Just to add something, we had started a similar discussion in iPhoneArt time ago, then decided to write something in the Apple Forum as well where you can find here the discussion. At the end of that discussion I added a link to a bug reported in Open radar that involve UIImageJPEGRepresentation, that you can read here, and that might be interesting for you to know. I don't know if this is another method used in the process, or one of the possibility you can use for saving the pictures on the camera roll.

This link in OpenRadar explain exactly what's going on and it shouldn't happen because when an image is saved using a method the quality shouldn't change so much to take out green part from it and convert it in purple/magenta. Devs can use probably different method to acquire the same results but if they are not aware about that particular bug are not to blame as well, in my opinion.

@Mikeraboy @Stackables Thank you Sam for the clarification about Tiff, Png and jpg. So we understand it's not so easy for the users to know what to do if they don't run a few test for each app.

If I well understood, just talking about Tiff for example, to avoid too much confusion. Let's say an app have both editing and shooting characteristics. If that app saves in Tiff it doesn't automatically mean that it edits in Tiff when pictures are imported from the camera roll to the same app, or that it sends in Tiff with the "open in..." feature right? Probably yes but it's not sure 100%, the app could use different conversion methods for each area, or not?

Yes, you understood correctly David. But more often than not, if an app doesn't save in a certain format say PNG, then it probably doesn't import / "open in" that format because why go through the trouble of supporting these secondary options and not the primary function of saving.

 

[Venomator]

FYI - I've shared the link on this discussion in whatever former IPA communities are out there (IPA Refugees, iPhoneart Studio Talk, iPhoneart Central). What makes MobiTog different and super valuable here is the active participation of developers - without that we'd all be flailing. !

@odilonvert - What a superstar MobiAmbassador you are Miss Jennifer...

Thank you kindly m'dear, for your continued and valued support...

And for spreading the gospel according to MobiTog.com...

 

[entusiasmo]

My advice: Upgrade to iOS 7 immediately! Filterstorm Neue is only available on iOS 7, and you should all be using it! It does not suffer from this issue as you can always save to Tiff, PNG, or Jpeg at arbitrary quality.

Hi Tai!
First of all, I love both your Filterstorm apps!
I'm actually using Filterstorm Neue as my favorite editing app (faaaaster than "old" Filterstorm, although I think Filterstorm has a better brush control with his size, softness and opacity controls ;-).

Sorry, but I noticed the same issue "purple tone + degradation of quality" with Filterstorm Neue on my iPhone 5S / IOS 7.0.5.
Below I attached the results of the test I made just few minutes ago with Filterstorm Neue, simply "open and save" (JPEG format, 100% quality) without editing, 12 times.

The original image (878 Kb)

The final image (1538 Kb), opening and saving 12 times with Filterstorm Neue (iPhone 5S, IOS7.0.5)

Crop of the original image / result image

My camera roll (quality degradation, step by step)

Thank you in advance for your reply, Tai!!
Mauro

PS. I still LOVE Filterstorm apps! ;-)))

 

[Mikeraboy]

It's conv

It's converted to JPG even if opened in another app. To test this, open a TIFF file in SnapSeed, then use "Open In..." to open in Big Photo. Check the photo info. It's JPG.

It depends on the app!

 

[Mikeraboy]

Hi Tai!
First of all, I love both your Filterstorm apps!
I'm actually using Filterstorm Neue as my favorite editing app (faaaaster than "old" Filterstorm, although I think Filterstorm has a better brush control with his size, softness and opacity controls ;-).

Sorry, but I noticed the same issue "purple tone + degradation of quality" with Filterstorm Neue on my iPhone 5S / IOS 7.0.5.

Mauro, what app did you use to take the photo and did you save it in camera roll before you sent it to FS .

 

[entusiasmo]

Mauro, what app did you use to take the photo and did you save it in camera roll before you sent it to FS .

Hi Michael, in this test I used native camera app, so the image was saved automatically to the camera roll.
Have you any (new) idea..?

 

[Tai Shimizu]

Hi Tai!
Sorry, but I noticed the same issue "purple tone + degradation of quality" with Filterstorm Neue on my iPhone 5S / IOS 7.0.5.

I hadn't had the chance to look for the purple issue before, just jpg compression.

Also, I just did the same test on 7.1, and got this, which seems reasonable for 10 saves with jpg compression. Not sure if that means the issue will be fixed or if something else is happening (i'm guessing the problem in ImageIO since it's coming up for you.)

 

[entusiasmo]

Ok, so I conducted the test in PhotoFusion running iOS 7 at 100% compression quality and here are the results. I, for one, didn't notice any deterioration in quality.

Original:
View attachment 50994

After 10 saves no editing
View attachment 50995

I'm a little bit confused, because I can reply the same issue using Photofusion on my iPhone 5S / IOS 7.0.5.
Below I attached the results of the test I made with Photofusion, simply open and save JPEG at 100% compression quality (without processing) 12 times.

Original image (taken with native camera, converted in BW and sended/received via email)

Final result (after 12 times)

Step by step (screenshot of my camera roll)

Crop of original/final image

I'm waiting for your reply, thank you in advance!!!

Mauro

 

[entusiasmo]

I hadn't had the chance to look for the purple issue before, just jpg compression.

Also, I just did the same test on 7.1, and got this, which seems reasonable for 10 saves with jpg compression. Not sure if that means the issue will be fixed or if something else is happening (i'm guessing the problem in ImageIO since it's coming up for you.)

This is a crop of your "final" image.

Yes, it seems not so bad compares to IOS7.0.5 test, but we can see again a general degradation of image quality (and "vertical lines issue").
With IOS6 I never noticed this issue before (as @odilonvert said), and because iPhone is "the most used camera in the world" it's unbelievable Apple didn't fix it yet.

 

[Russ]

It depends on the app!

Mike, every app that I've tried that has the "Open In..." feature, and that does not save in TIFF, converts to JPG when exporting what were TIFF files with the "Open In..." feature.

 

[odilonvert]

@Venomator - my pleasure! The fact that developers participate here in discussion is extremely special - I value this very much! It rarely happens in the groups I visit regularly.

 

[Stackables]

I'm a little bit confused, because I can reply the same issue using Photofusion on my iPhone 5S / IOS 7.0.5.
Below I attached the results of the test I made with Photofusion, simply open and save JPEG at 100% compression quality (without processing) 12 times.

Original image (taken with native camera, converted in BW and sended/received via email)
View attachment 51060

Final result (after 12 times)
View attachment 51061

Step by step (screenshot of my camera roll)
View attachment 51062

Crop of original/final image
View attachment 51063 View attachment 51064

I'm waiting for your reply, thank you in advance!!!

Mauro

Mauro, thanks for taking the time to conduct this test.

I find the results very surprising! I'm not sure what's happening here. We'll investigate the matter further tomorrow, but in the meantime could you answer the following questions?

1 - Do you see this only in photos shot with your iPhone 5s?
2 - Did you see the same results in other images that you tested?
3 - How did you convert to black and white?
4 - What are the pixel dimensions of the image?
5 - Did you shoot the image in square format or did you crop it afterwards?
6 - Do you see the same results in colored images?

Thanks
Sam

 

[odilonvert]

#6 question is esp interesting - on IPA many use a b&w style so the purple thing was noticeable - and really bad news - right away

 

[Mikeraboy]

Now I am really confused about jpeg compression. Does different,Camera apps make a difference, does taking a picture and then transferring it with photo transfer to ipad degrade the image and the what editor should you use? I will let the developers comment. In the meantime, I will stick with 3 camera apps:
1. PureShot and 645Pro. Tiff
2: Cortex Cam Png
3: KitCamera Tiff

I will edit in FS-Tiff, Leonardo-PNG. PhotoFusion -PNG or Snapseed, iColorama, and open in to FS and save as tiff. I haven't had the problem of vertical streaks or color degradation. As I said, I am using 5s, 7.06 and Ipad3. I save my pics in Dropbox ,so memory is not a problem. It would be faster and more convenient to use Jpegs, I am not much of a photographer, and I do a lot of editing! The tests are using ten saves, I probably do ten edits going back and forth between apps. I am sticking with Lossless. Now I will be quiet and listen. The developers are the experts, I am just shooting from the hip!

 

[Mikeraboy]

Mike, every app that I've tried that has the "Open In..." feature, and that does not save in TIFF, converts to JPG when exporting what were TIFF files with the "Open In..." feature.

If you use an app that says open in and you open in Filterstorm, then you can save file as tiff in FS. The app is not saving the file, you are just transferring it to FS where it gets saved. I am not an expert, but seems to be what's happening.

 

[Russ]

If you use an app that says open in and you open in Filterstorm, then you can save file as tiff in FS. The app is not saving the file, you are just transferring it to FS where it gets saved. I am not an expert, but seems to be what's happening.

Mike, the app is sending a jpg file to Filterstorm. You then have the option to save it in one of three formats, including TIFF. The issue is that degradation has occurred, and saving it as TIFF won't revert that.

 

[Mikeraboy]

I am trying to understand ,as well, if an app accepts a tiff , how do you know it becomes a jpeg, it hasn't been saved. I thought the degradation comes from repeated opening and saving a file. It's not the editing that degrades a jpeg, but the editing and then saving. It doesn't get compressed until it is saved. Would a developer please explain this to me! Where is Mike Hardaker when you need him. ( just kidding)

 

[odilonvert]

The guess is that Apple has degraded the quality of the image initially shot to make room for its new OS. So you're operating with an inferior file from the get-go, not like before.

To me that seems like a very weird choice for Apple to make though. I thought the idea was to put in better and better cameras every hardware update - why bother if you're going to keep the file size less than acceptable just to have room for the O.S.? Apple makes great products for professional artists, it's built its reputation on that. Why would it do such a thing to a file before it lands in an app for editing? That's like biting the hand that feeds you. Or is using the phone as a camera not really their priority? Does one need to go to Nokia for that now?... Samsung?... Very weird.