Bitmap Manipulation

BitmapManipulation.kt

/* 
    Sample Parameter: 
    String: "file:///storage/emulated/0/Android/data/com.example.disappeardents/cache/roof_1.jpg"
 */
fun uriStringToBitmap(uriString : String) : Bitmap {

    val uri = uriString.toUri()
    val uriPath = uri.path
    val bitmap = BitmapFactory.decodeFile(uriPath)

    return bitmap

}

/* 
    Sample Parameter: 
    1: Bitmap: [bitmap]
    2: String: "my_file_name.jpg"
 */
fun bitmapToUriString(bitmap: Bitmap, fileName: String) : Uri{

    // set directory where it will be stored (on cache)
    var file = File(activity!!.externalCacheDir, fileName)

    // save the image on cache
    var fOut = FileOutputStream(file)
    bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fOut)

    // get the path of the image
    var uriPath = Uri.fromFile(file)

    return uriPath

}

fun rescaleBitmap(uriString : Uri) : Bitmap {

        val uriPath = uriString.path
        val bitmap = BitmapFactory.decodeFile(uriPath)
        val maxSize = 800
    
        println("size: " + bitmap.byteCount)
        println("width: " + bitmap.width)
        println("height: " + bitmap.height)

        var width = bitmap.width
        var height = bitmap.height

        val bitmapRatio = width / height;
        if (bitmapRatio > 1) {
            width = maxSize
            height = (width / bitmapRatio)
        } else {
            height = maxSize
            width = (height * bitmapRatio)
        }

        val rescaledBitmap = Bitmap.createScaledBitmap(bitmap, width, height, true)

        println("new size: " + rescaledBitmap.byteCount)
        println("new width: " + rescaledBitmap.width)
        println("new height: " + rescaledBitmap.height)

        return rescaledBitmap
    }