Is there any multiplatform class in stdlib or some library which can manipulate with images?

# multiplatform

[electrolobzik]

Is there any multiplatform class in stdlib or some library which can manipulate with images?

[Michael Paus]

What kind of manipulations do you have in mind?

[electrolobzik]

I have a ByteArray and need some function like Android’s Bitmap.getPixels .

[Michael Paus]

If you are using this in conjunction with Compose you can use functions like this:

Image.makeFromEncoded(encodedImageData).toComposeImageBitmap()

SKIA provides such import/export functions for images.

[electrolobzik]

@Michael Paus Do you know why I am getting an error with this line:

val bitmap: ImageBitmap = remember { org.jetbrains.skia.Image.makeFromEncoded(image).toComposeImageBitmap() }

I get Unresolved reference: toComposeImageBitmap during the build process, while IDE doesn’t show errors. I am using in in the compose shared module. Targeting Android.

[Michael Paus]

For Android you have to use

BitmapFactory.decodeByteArray(encodedImageData, 0, encodedImageData.size).asImageBitmap()

because we don’t have Skia access on Android.

[electrolobzik]

hmm, so I can’t make compose multiplatform code with Image showing image from a ByteArray without using expect/actual converter function?

[electrolobzik]

Thank you a lot!

[Michael Paus]

I just answered the exact same question here just a few minutes ago 😉: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1705255315788899

[electrolobzik]

I didn’t realise that it was the same topic, thank you! It is a bit weird that IDE doesn’t show any errors here

[electrolobzik]

Otherwise it will be more clear what direction one should investigate

[Michael Paus]

Yes, that is weird but I got used to it because that happens so often 🤨.

[electrolobzik]

@Michael Paus Do you by any chance know any simple solution to make Image show the image rotated corresponding to its EXIF? Do I have to read Exif and manually rotate it or is there any build-in mechanism?

[Michael Paus]

You probably have to do the rotation yourself via a rotation transform but you can easily read the flag via https://github.com/Ashampoo/kim