Picassoで円形に切り取った画像に枠線を付ける

import android.graphics.*
import com.squareup.picasso.Transformation

class BorderedCircleTransform(
    private val borderColor: Int,
    private val borderSize: Int
) : Transformation {

    override fun transform(source: Bitmap?): Bitmap? {
        source ?: return null

        val size = Math.min(
            source.width,
            source.height
        )

        val x = (source.width - size) / 2
        val y = (source.height - size) / 2

        val squaredBitmap = Bitmap.createBitmap(
            source,
            x,
            y,
            size,
            size
        )

        if (squaredBitmap != source) {
            source.recycle()
        }

        val bitmap = Bitmap.createBitmap(
            size,
            size,
            source.config
        )

        val canvas = Canvas(bitmap)
        val paint = Paint().apply {
            shader = BitmapShader(
                squaredBitmap,
                Shader.TileMode.CLAMP,
                Shader.TileMode.CLAMP
            )
            isAntiAlias = true
        }

        val r = size / 2f
        Canvas(bitmap).drawCircle(
            r,
            r,
            r,
            paint
        )

        val paintBg = Paint().apply {
            color = borderColor
            isAntiAlias = true
        }

        canvas.drawCircle(
            r,
            r,
            r,
            paintBg
        )

        canvas.drawCircle(
            r,
            r,
            r - borderSize,
            paint
        )

        squaredBitmap.recycle()

        return bitmap
    }

    override fun key(): String = "bordered_circle"
}

        Picasso.get()
            .load(URL)
            .transform(
                BorderedCircleTransform(
                    borderColor = Color.RED,
                    borderSize = 4
                )
            )
            .into(image_view_bordered_circle)