Exif data on Android gets lost even with keepExif = true

[yannickvg]

On Android we seem to lose a lot of exif data from a picture when compressing it, even with keepExif: true .

Example

before scaling:

{Image ImageWidth: 4032, Image ImageLength: 3024, Image Make: samsung, Image Model: SM-G970F, Image Orientation: Rotated 90 CW, Image XResolution: 72, Image YResolution: 72, Image ResolutionUnit: Pixels/Inch, Image Software: G970FXXU8DTH7, Image DateTime: 2020:09:16 16:54:42, Image YCbCrPositioning: Centered, Image ExifOffset: 238, GPS GPSLatitudeRef: N, GPS GPSLatitude: [51, 8, 1321017/25000], GPS GPSLongitudeRef: E, GPS GPSLongitude: [4, 26, 119523/12500], Image GPSInfo: 656, Thumbnail ImageWidth: 512, Thumbnail ImageLength: 384, Thumbnail Compression: JPEG (old-style), Thumbnail XResolution: 72, Thumbnail YResolution: 72, Thumbnail ResolutionUnit: Pixels/Inch, Thumbnail JPEGInterchangeFormat: 876, Thumbnail JPEGInterchangeFormatLength: 58490, EXIF ExposureTime: 1/100, EXIF FNumber: 12/5, EXIF ExposureProgram: Program Normal, EXIF ISOSpeedRatings: 50, EXIF ExifVersion: 0220, EXIF DateTimeOriginal: 2020:09:16 16:54:42, EXIF DateTimeDigitized: 2020:09:16 16:54:42, EXIF ShutterSpeedValue: 1/100, EXIF Aperture ....

after scaling:

{Image ImageWidth: 2064, Image ImageLength: 2752, Image ExifOffset: 62, Image Orientation: 0, EXIF LightSource: Unknown}

Flutter version: Channel stable, 1.20.4

We see it happen on devices from different vendors, different Android versions, ...

[CaiJingLong]

The part of code copy from flutter team. It seems that there are restrictions on the retention of tags.

[MathiasCochet]

This should be fixed in this PR: https://github.com/OpenFlutter/flutter_image_compress/pull/161 @CaiJingLong