is there any library that convert imagebitmap to png of bytearray?

# multiplatform

[juhaodong]

is there any library that convert imagebitmap to png of bytearray?

[alexandre mommers]

Korge have a lot of methods to manipulate images https://korge.org/

On this projet for example, I read png, then extract raw bitmap bytearray to send them to the GPU :
https://github.com/wgpu4k/wgpu4k/blob/main/wgpu4k-scenes/src/commonMain/kotlin/io.ygdrasil.wgpu.examples/AssetManager.kt
https://github.com/wgpu4k/wgpu4k/blob/main/wgpu4k-scenes/src/jvmMain/kotlin/io.ygdrasil.wgpu.examples/AssetManager.jvm.kt
https://github.com/wgpu4k/wgpu4k/blob/main/wgpu4k-scenes/src/androidMain/kotlin/io.ygdrasil.wgpu.examples/AssetManager.android.kt
https://github.com/wgpu4k/wgpu4k/blob/main/wgpu4k-scenes/src/nativeMain/kotlin/io.ygdrasil.wgpu.examples/AssetManager.native.kt
https://github.com/wgpu4k/wgpu4k/blob/main/wgpu4k-scenes/src/jsMain/kotlin/io.ygdrasil.wgpu.examples/AssetManager.js.kt

You need to check the API, but I think you can find what you need

[juhaodong]

yeah, but now I need to actually convert the imageBitmap from Compose to byteArray, that is all about loading from an actually bitmap

[alexandre mommers]

My bad, may be you will get more specific answer on the #CJLTWPH7S channel

[juhaodong]

thanks for your help bro

[Michael Paus]

Give this a try:

expect fun ImageBitmap.encodeToPngBytes(quality: Int = 100): ByteArray?

// Android
actual fun ImageBitmap.encodeToPngBytes(quality: Int): ByteArray? {
    ByteArrayOutputStream().use { bytes ->
        this.asAndroidBitmap().compress(Bitmap.CompressFormat.PNG, quality, bytes)
        return bytes.toByteArray()
    }
}

// On all other platforms
actual fun ImageBitmap.encodeToPngBytes(quality: Int): ByteArray? {
    return Image.makeFromBitmap(this.asSkiaBitmap()).encodeToData(org.jetbrains.skia.EncodedImageFormat.PNG, quality)?.bytes
}