Blur and stretch

Sometimes when you change canvas size of your image you want to use something more fancy than plain solid color as a background. One of possible solutions is to use blurred version of your image as a background. Basically this guide shows one possible way to achieve it using basic Image operations and blur filter (LensBlurFilter was chosen as an example).

You just need to: 1. scale image to desired dimensions to make a foreground, e.g. using scaleToRatio. In code below this step is omitted for simplicity: val fgImage = image 2. scale image using cover and apply some blur via filter to make a background 3. complete process by putting foreground on top of background using overlay

import java.nio.file.Paths

import com.sksamuel.scrimage.{Image, ScaleMethod}
import com.sksamuel.scrimage.filter.LensBlurFilter

val image = Image.fromPath(Paths.get("examples", "images", "lanzarote_small.jpeg"))
val filter = new LensBlurFilter(12f, 2f, 255f, 10)
// for simplicity of example source image is not scaled
val fgImage = image
val targetWidth = fgImage.width * 2
val targetHeight = fgImage.height
image
  .cover(targetWidth, targetHeight, ScaleMethod.FastScale)
  .filter(filter)
  .overlay(fgImage, x = (targetWidth - fgImage.width) / 2, y = (targetHeight - fgImage.height) / 2)

Compare original and result:

Before	After