Scaling Stylized Parameters
The size of an image will sometimes affect how other parameters are applied. In the case of Pixellate, Gaussian Blur or Halftone the size of an image will influence the visual effect of these three parameters.
Take these two images, for example:
Even if they have the same blur value, the blur parameter affects both of these images differently,
The value of the blur parameter must be scaled appropriately to achieve an identical blur effect between both images.
How to Scale
You can approach this with a bit of math. We can start with the two images with different aspect ratios. They both have blur=25, but the blur effect looks more pronounced on the left image because of the dimension difference.
Step 1
The first step would be to get the total dimension for each image.
Image #1: 650 h * 250 w = 162500
Image #2: 250 h * 900 w = 225000Step 2
Next, we can divide the total dimension of image two by image 1 to get the ratio of the size difference.
225000 / 162500 = ~1.38Step 3
Finally, we can multiply our original blur value by the ratio we received in step 2.
25 * 1.38 = ~34.5The Finished Result
After you receive your scaled-up blur value, you can apply it to your second image and see that the amount of blur between them is now the same.
Using this method, you can ensure that your images have a uniform effect no matter the dimensions or aspect ratio of your images.