[Kotlin] Bitmap

Android CameraX 와 TensorFlow Lite 사용하면서 ...

ByteArray -> Bitmap

fun ByteArray.toBitmap(): Bitmap? {
    return BitmapFactory.decodeByteArray(this, 0, this.size)
}

android.media.image -> Bitmap

fun Image.toBitmap(): Bitmap {
            val yBuffer = planes[0].buffer // Y
            val vuBuffer = planes[2].buffer // VU

            val ySize = yBuffer.remaining()
            val vuSize = vuBuffer.remaining()

            val nv21 = ByteArray(ySize + vuSize)

            yBuffer.get(nv21, 0, ySize)
            vuBuffer.get(nv21, ySize, vuSize)

            val yuvImage = YuvImage(nv21, ImageFormat.NV21, this.width, this.height, null)
            val out = ByteArrayOutputStream()
            yuvImage.compressToJpeg(Rect(0, 0, yuvImage.width, yuvImage.height), 50, out)
            val imageBytes = out.toByteArray()
            return BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size)
        }

Rotate Bitmap

val matrix = Matrix().apply {
            postRotate(90F)
        }

val createBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, matrix, false)

CameraPreview 안에 있는 뷰 크기만큼 자르는 방법

private fun cropImage(bitmap: Bitmap, cameraPreview: View, innerView: View): ByteArray {

        val heightOriginal = cameraPreview.height // preview height
        val widthOriginal = cameraPreview.width // preview width
        val heightFrame = innerView.height
        val widthFrame = innerView.width


        val heightReal = bitmap.height
        val widthReal = bitmap.width
        val widthFinal = widthFrame * widthReal / widthOriginal
        val heightFinal = heightFrame * heightReal / heightOriginal

        val maxX = cameraPreview.width - innerView.width
        val maxY = cameraPreview.height - innerView.height

        val leftFrame = if (innerView.x.toInt() < 0) {
            0
        } else if (innerView.x.toInt() > maxX) {
            maxX
        } else {
            innerView.x.toInt()
        }

        val topFrame = if (innerView.y.toInt() < 0) {
            0
        } else if (innerView.y.toInt() > maxY) {
            maxY
        } else {
            innerView.y.toInt()
        }


        val bitmapFinal = Bitmap.createBitmap(
            bitmap,
            leftFrame, topFrame, widthFinal, heightFinal
        )
        val stream = ByteArrayOutputStream()
        bitmapFinal.compress(
            Bitmap.CompressFormat.JPEG,
            100,
            stream
        ) //100 is the best quality possible
        return stream.toByteArray()
    }