Starlite Posted March 20, 2021 Share Posted March 20, 2021 I have an image that is a map (snippet below). I'd like to use this in Google Sheets, but they don't allow background images. So I have a plan to convert the map, but I need some help. The idea is to use edge detection to strengthen all the edges to black, then somehow select all the other regions and delete them, converting them to transparency. I'm having two issues: 1. How do I make the lines strong enough between zones? (Outline seemed to work, but Edge Detection destroyed that strength.) 2. How do I select all areas under a certain luminance threshold, in order to delete them? I'm happy for the map to be black and white, though starting with colour may have some advantages. Thanks in advance, for any help! PS: Please test your ideas on the image snippet I've provided before suggesting them. That seems the best way to ensure they actually work. :) Quote Link to comment Share on other sites More sharing options...
Red ochre Posted March 20, 2021 Share Posted March 20, 2021 This may help Tone Gradient Magnitude Reduce background opacity and if needed you can subsequently adjust the opacity of the remaining lines using Alpha-threshold 1 Quote Red ochre Plugin pack.............. Diabolical Drawings ................Real Paintings Link to comment Share on other sites More sharing options...
Starlite Posted March 20, 2021 Author Share Posted March 20, 2021 Sweet. I'll try it out. Quote Link to comment Share on other sites More sharing options...
Ego Eram Reputo Posted March 21, 2021 Share Posted March 21, 2021 21 hours ago, Starlite said: 2. How do I select all areas under a certain luminance threshold, in order to delete them? Have you tried the magic wand with the Shift key held down? The Shift key toggles Global selection. Once you've made a selection using the Shift key, fine tune it using the Tolerance setting to include or exclude pixels. 1 Quote ebook: Mastering Paint.NET | resources: Plugin Index | Stereogram Tut | proud supporter of Codelab plugins: EER's Plugin Pack | Planetoid | StickMan | WhichSymbol+ | Dr Scott's Markup Renderer | CSV Filetype | dwarf horde plugins: Plugin Browser | ShapeMaker Link to comment Share on other sites More sharing options...
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