ocr-parsing-drawing.kt

val blocks = text.blocks
val blocksRect = blocks.mapNotNull { it.boundingBox }

val lines = blocks.flatMap { it.lines }
val linesRect = lines.mapNotNull { it.boundingBox }

val elements = lines.flatMap { it.elements }
val elementsRect = elements.mapNotNull { it.boundingBox }

// copy bitmap and make it mutable if necessary (optional step)
// depends on how do you get your bitmap
val mutableBitmap = inputBitmap.copy(inputBitmap.config, true) 

// draw all bounding boxes on bitmap
with(Canvas(mutableBitmap)) {
   blocksRect.forEach { drawRect(it, blocksPaint) }
   linesRect.forEach { drawRect(it, linesPaint) }
   elementsRect.forEach { drawRect(it, elementsPaint) }
}
imageView.setImageBitmap(mutableBitmap)