add a small radius to imageview android code example
Example: round corner imageview android
Transformation transformation = new RoundedTransformationBuilder()
.borderColor(Color.BLACK)
.borderWidthDp(3)
.cornerRadiusDp(30)
.oval(false)
.build();
Picasso.with(context)
.load(url)
.fit()
.transform(transformation)
.into(imageView);