https://bugs.kde.org/show_bug.cgi?id=374972
--- Comment #5 from David REVOY <i...@davidrevoy.com> --- Created attachment 103415 --> https://bugs.kde.org/attachment.cgi?id=103415&action=edit [picture of steps to understand the description of the RedRobes highpass method] Yes, I agree. it's a feature request. I was curious about the Gimp plugin and @Deo usage about the option 'Redrobes'; an option *I didn't know* about high-pass. The result is good: better than other 'high-pass' filter I used before (even GMIC one). Here is the core informations I found about it [1] : The GIMP plugin filter propose 5 Highpass methods: 1. Colour - a classic high-pass similar to Ps. 2. Preserve DC - like colour, but adds the average image colour back in. 3. Greyscale - turn to greyscales the layer before high pass filtering. 4. Greyscale, Apply Chroma - as above, but blends it in with the source layer colours 5. Redrobes ( read down this post ) The basic steps used for all filters ( except "Redrobes" one) : -duplicate layer -blur the duplicate -invert the duplicate -set the duplicate to 50% opacity, keeping the mode "normal" -merge it down. (This gives the hpf with a base 10 50% grey.) The Redrobes one is a bit more complex: ( see image in attachment, for reference ) -Get an image 1. -Blur it quite a lot 2. -Blur it until its a constant colour 3. -Use Image arithmetic to generate 2 - 3 => 4 -Use Image arithmetic to generate 3 - 2 => 5 -Take 1 and subtract 4 and add 5 => 6 [1] this information, attachement were created and quoted from RobA and RedRobes (creator of the plugin) on the forum cartographerguild.com, main thread: link: https://www.cartographersguild.com/showthread.php?t=2582 to be used here later as references. -- You are receiving this mail because: You are watching all bug changes.
