Android, GPUImage, get image filtered

- set Uri, get bitmapWithFilterApplied --> NG : NPE

var imageUri : Uri? = data?.data

val gpuImage = GPUImage(this)
gpuImage.setImage(imageUri)
gpuImage.setFilter(GPUImageColorInvertFilter())
mainImageView?.setImageBitmap(gpuImage.bitmapWithFilterApplied)

- set Bitmap, get bitmapWithFilterApplied --> OK

val gpuImage = GPUImage(this)
val editedImage : BitmapDrawable = mainImageView?.drawable as BitmapDrawable
gpuImage.setImage(editedImage.bitmap)
gpuImage.setFilter(GPUImageColorInvertFilter())
mainImageView?.setImageBitmap(gpuImage.bitmapWithFilterApplied)