Rectangular to Polar filter

[Kasper-V]

There was a bug in Photo's rectangular to polar filter, which has been fixed recently. But there is still a puzzling effect, as these pics show. I made a grid of squares, with a border one pixel wide, then applied the filter (Filters>Distort>Polar to rectangular); then I applied the same transformation to the original image with Paint Shop Pro X6 ...

 

Original

 

AP

 

PSP

 

AP has expanded the one-pixel border to 87 pixels (the while image is 600 pixels wide) and shrunk the rest to fit, while PSP has maintained the dimensions. When the reverse transform is applied -- polar to rectangular -- AP returns the original (apart from a little expected distortion), but omits the extra border when applied to the PSP image ...

 

 

Any thoughts?

[firstdefence]

Grid of squares canvas size 100mm x 100mm Squares 25mmx25mm 

 

I get a different effect from you on Polar to Rectangular, this is a "Group" of squares - no border:

 

...and with no border and Rectangular to Polar I get:

 

This is a merged visible layer.

 

Note: Photoshop behaves like Affinity.

 

 

[Kasper-V]

52 minutes ago, firstdefence said:

I get a different effect from you on Polar to Rectangular, this is a "Group" of squares - no border:

 

Just realised I made a mistake up there! I typed Filters>Distort>Polar to rectangular and it should have been Filters>Distort>Rectangular to polar. Sorry -- I've confused the issue. But the rest of my post stands.

[Alfred]

With no border there is no gap when I apply the 'Rectangular to Polar' filter, but if I start with a border around the group of squares I do get a gap. The bigger the border, the bigger the gap.

 

[firstdefence]

Just tried this in GIMP and it behaves as PaintShop Pro (PSP) does in Rectangular to Polar and as Photoshop does in Polar to Rectangular.

 

 

 

I like Gimps filter window and to a lesser extent Photoshops approach to the polar filter, being able to see a preview and flip between settings is a nice feature that Affinity should have, instead of having two separate filters with no controls.

[Kasper-V]

PSP is similar. The extra parameters can be useful, and would be an asset in AP.