[image_picker] iOS: save image to the correct type based on its original type and copy over exif data from the original image #1586

cyanglaz · 2019-05-09T20:20:50Z

Description

Previously, our implementation checks the alpha of the UIImage object to determine the type (png or jpeg). This PR refactored the code to actually check the original image file's type to determine the type it should be saved. Which makes it safer.

While doing so, we also copied the exif data from the original image, now the picked image has the correct exif data.

Since iOS doesn't support converting UIImage to NSData for types other than PNG or JPEG, we are currently only supporting these 2 types. (If anyone knows how to convert UIImage to other types:gif or tiff, we can add them as well)

XCTests target is also added in this PR. So we can start adding iOS unit tests in image picker.

This is a follow up of #742
And this PR is the first step to achieve what we were trying to do in #866.

Thanks to @ko2ic for inspiration of some of the works in this PR.

We will need follow up PR to support GIF if possible, as well as copying GPS data over.

Related Issues

flutter/flutter#31751
flutter/flutter#17947
flutter/flutter#12921

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]). This will ensure a smooth and quick review process.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md and increment major revision).
No, this is not a breaking change.

cyanglaz · 2019-05-09T20:26:37Z

@ko2ic This PR is inspired by your PR in #866
Do you mind review this? :)

ko2ic

@cyanglaz It's getting really good.

I have made some comments.
I think especially gif can be supported.

ko2ic · 2019-05-10T00:27:45Z

AUTHORS

+Ozkan Eksi <ozeksi@gmail.com>
+ko2ic <ko2ic.sal@gmail.com>


Please use the e-mail address below.

ko2ic <ko2ic.dev@gmail.com>

ko2ic · 2019-05-10T01:42:12Z

packages/image_picker/ios/Classes/ImagePickerPlugin.m

+                     NSData *data = [ImagePickerMetaDataUtil convertImage:image
+                                                                usingType:type
+                                                                  quality:nil];
+                     NSString *fileExtension = [@"image_picker_%@" stringByAppendingString:suffix];


In case of type == FlutterImagePickerMIMETypeOther, suffix will be nil.
Therefore, a crash occurs.

It is more convenient to treat as jpeg than not to support FlutterImagePickerMIMETypeOther.

ko2ic · 2019-05-10T01:55:36Z

packages/image_picker/ios/Classes/ImagePickerMetaDataUtil.h

+// quality with type other than FlutterImagePickerMIMETypeJPEG. Converting UIImage to
+// FlutterImagePickerMIMETypeGIF or FlutterImagePickerMIMETypeTIFF is not supported in iOS. This
+// method throws exception if trying to do so.
+ (nonnull NSData *)convertImage:(nonnull UIImage *)image


If the argument type here is not UIImage but NSData, it can handle gif images.

Please refer to the following.

https://github.com/flutter/plugins/pull/866/files#diff-ce2e9c98db20f69ecf981788585d7a87R209

This will be able to also handle animated gif.

I think we can add the gif handling in a separate PR. I also want to take a deeper dive into the implementation to see if there is a way to support scaling gif. If not, then we need to decide how to handle when people passed the scaling factors into the API.

cyanglaz · 2019-05-14T22:02:02Z

@ko2ic Thanks for doing this. I updated the PR with you comments! I also added the exif in this PR. Do you mind to take another look?

ko2ic

@cyanglaz I tried it, but the creationDate of Exif is different.
Timezone seems to be irrelevant.
It gets as 16 hours ago.

cyanglaz · 2019-05-15T16:27:47Z

@ko2ic That's strange, all I did was just copying everything over, I will take a look again.

cyanglaz · 2019-05-15T16:56:42Z

@ko2ic I just checked and it seems working for me? Could you post the steps of your testing here?

ko2ic · 2019-05-16T02:38:16Z

@cyanglaz It works without problem in unit test but I get problems when I run it on the simulator.

I put a breakpoint on line 31 in ImagePickerPhotoAssetUtil.m and I confirmed ExifDateTimeOriginal.
The selected image is an image in the simulator.

Please check the image below.

cyanglaz · 2019-05-16T03:08:42Z

@ko2ic Thank you. I tested with the steps you provided and I found out that the time that shows up in photo app in the simulator does depend on the time zone of your computer. Somehow the time in the metadata is based on Pacific time and it just matched my local time. If you set your mac to pacific timezone, and reopen the photo app in the simulator, you will see the time match the time in the exif.

ko2ic · 2019-05-16T10:10:22Z

@cyanglaz I do not mind if this is a problem with mac and simulator.

cyanglaz · 2019-05-16T16:43:47Z

@ko2ic Thanks! Other than that, do you see any issues or improvements that can be done in the code?

ko2ic · 2019-05-20T14:50:59Z

@cyanglaz No problem. Please go ahead and proceed with it.

Follow up #1586. Copying over all the metadata, including GPS, orientation and more. Note that because orientation is copied, we have to revert the orientation that iOS has done on the picked image to make the image show up in a correct way on the phone.

* iOS: Using first byte to determine original image type. (Only JPEG and PNG) * iOS: Added XCTest target. * iOS: The picked image now has the correct EXIF data copied from the original image.

googlebot added the cla: yes label May 9, 2019

cyanglaz force-pushed the image_picker_ios_file_type_refactor branch from 640715f to 8dc06ef Compare May 9, 2019 20:22

cyanglaz changed the title ~~[image_picker] iOS: save image to different types based on its original type.~~ [image_picker] iOS: save image to the correct type based on its original type. May 9, 2019

ko2ic reviewed May 10, 2019

View reviewed changes

cyanglaz mentioned this pull request May 10, 2019

[image_picker] Fix exif orientation for pictures taken from camera #1392

Closed

cyanglaz changed the title ~~[image_picker] iOS: save image to the correct type based on its original type.~~ [image_picker] iOS: save image to the correct type based on its original type and copy over exif data from the original image May 14, 2019

Image picker meta data corrections

019791e

cyanglaz force-pushed the image_picker_ios_file_type_refactor branch from 2bf6896 to 019791e Compare May 14, 2019 22:05

ko2ic reviewed May 15, 2019

View reviewed changes

merge master

46359fb

cyanglaz merged commit 7c23d31 into flutter:master May 20, 2019

cyanglaz deleted the image_picker_ios_file_type_refactor branch May 20, 2019 20:42

cyanglaz mentioned this pull request May 20, 2019

[image_picker] ios: copy all meta data from the original image. #1617

Merged

13 tasks

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[image_picker] iOS: save image to the correct type based on its original type and copy over exif data from the original image #1586

[image_picker] iOS: save image to the correct type based on its original type and copy over exif data from the original image #1586

cyanglaz commented May 9, 2019 •

edited

Loading

cyanglaz commented May 9, 2019

ko2ic left a comment

ko2ic May 10, 2019

ko2ic May 10, 2019

ko2ic May 10, 2019 •

edited

Loading

cyanglaz May 14, 2019

cyanglaz commented May 14, 2019 •

edited

Loading

ko2ic left a comment

cyanglaz commented May 15, 2019

cyanglaz commented May 15, 2019

ko2ic commented May 16, 2019 •

edited

Loading

cyanglaz commented May 16, 2019

ko2ic commented May 16, 2019

cyanglaz commented May 16, 2019

ko2ic commented May 20, 2019

[image_picker] iOS: save image to the correct type based on its original type and copy over exif data from the original image #1586

[image_picker] iOS: save image to the correct type based on its original type and copy over exif data from the original image #1586

Conversation

cyanglaz commented May 9, 2019 • edited Loading

Description

Related Issues

Checklist

Breaking Change

cyanglaz commented May 9, 2019

ko2ic left a comment

Choose a reason for hiding this comment

ko2ic May 10, 2019

Choose a reason for hiding this comment

ko2ic May 10, 2019

Choose a reason for hiding this comment

ko2ic May 10, 2019 • edited Loading

Choose a reason for hiding this comment

cyanglaz May 14, 2019

Choose a reason for hiding this comment

cyanglaz commented May 14, 2019 • edited Loading

ko2ic left a comment

Choose a reason for hiding this comment

cyanglaz commented May 15, 2019

cyanglaz commented May 15, 2019

ko2ic commented May 16, 2019 • edited Loading

cyanglaz commented May 16, 2019

ko2ic commented May 16, 2019

cyanglaz commented May 16, 2019

ko2ic commented May 20, 2019

cyanglaz commented May 9, 2019 •

edited

Loading

ko2ic May 10, 2019 •

edited

Loading

cyanglaz commented May 14, 2019 •

edited

Loading

ko2ic commented May 16, 2019 •

edited

Loading