Custom Blur Tool

[Panlumix]

Could anyone explain the use of the custom blur tool,and how to use this in a workflow.I have played around with it for a little while and can see that it does create a blur effect,however what effect do the input numbers effect the image in a specific way.Also can these inputs be saved and used in other editing another image.

[stokerg]

Hi Panlumix,

I can't give a workflow example, as i've never had use for this but i'm sure someone else can.  Our help file gives a good break down of the options on the dialog here

You can't save these out of Affinity in a file for use in other software.  But the any other software this kind of custom blur feature should have a similar layout and the same values should give the same results  

[dmstraker]

I've done a few YouTube videos on Custom Blur:

https://www.youtube.com/results?search_query=inaffinity+custom+blur

[R C-R]

As @stokerg said, the help file explains how the numbers matrix affect each pixel's brightness. But since it could be a bit difficult to see how that works with a normal photo, you might find experimenting with this 5x5 Custom blur test.afphoto file makes it a little clearer.

It is a tiny file, only 25 x 45 px, so I suggest zooming in to 1000% or 1500%. (The file has those 2 viewpoints built in.) The 8 rectangular shapes on the pixel layer are each 5x5 px, just like the matrix, spaced 5 px apart, & aligned to the grid:

Hopefully, this will make it easy to see the effect of changing the numbers in the matrix at the pixel level.

[HansWerner]

Hi, the custom blurr filter is a very fine filter, it can be used to blurr as well to sharpen images. The way the parameter ranges have to be selected and the name that has been given to this "blurr" filter (it is a "band pass filter" gives me the feeling that the function of the filter has not been completely understood at affinity. I give simple examples: -1 in the upper left field and +1 in the lower right field (zeros elsewhere), offset is sharpening (high pass) filter emphasizing edges running at an angle of 45 degree. +1 in the upper left field and +1 in the lower right corner of the matrix (zeros elsewhere) blurs the image only in the direction of the diagonal line. The high pass version can be used to generate relief effects (see the results below achieved in photoshop). To remedy: Normalize is a dangerous non-necessary feature, as it could imply division by zero. Offset should add a color value to each channel between 0 and 255 (8 byte) to the matrix results. The examples here were achieved with PS: https://www.mapdesign.info/kontakt/example/