#### Summary: <!-- Summarize the issue/suggestion concisely: --> PNG crashes while using the Centerline feature of Trace Bitmap #### Steps to reproduce: <!-- Describe what you did (step-by-step) so we can reproduce: --> - Open .png - Select image on canvas - Open Trace Bitmap dialog and select Centerline - Click preview and trace appears within the preview area [TraceBitmapDialog](/uploads/ffa5ddeb26f87833a5fc17680d5e365e/TraceBitmapDialog.png) - Click OK, error modal #### What happened? Inkscape closes with a modal [CenterlineCrash](/uploads/eebb6ea39767ef181d40388e4e6a4022/CenterlineCrash.png) #### What should have happened? Vector paths are created and Inkscape does not crash / close. If I use Autotrace first (successful) and then run Centerline, the modal is different. [CenterlineCrashAfterAutotrace](/uploads/0be4512b07179e2c8939729c955bf278/CenterlineCrashAfterAutotrace.png) Note that the temporary .svg created has no additional data in it. It only contains the .png import. Sample attachments: Image causing the issue. [WaveSingleLineOriginal](/uploads/ad3fbb19aaffbf7df946c2d692dbf7d5/WaveSingleLineOriginal.png) #### Version Info: - Inkscape Version: 1.0.1 (3bc2e813f5, 2020-09-07) (running as an extracted .7z, not installed) - Operating System: Windows 10 - Operating System version: 10.0.18363 Build 18363