Paint.NET 4.1.5

This update focuses on improving performance (sometimes significantly) and fixing important bugs:
Improved: Image -> Rotate should now complete almost instantly (thanks @Bruce Bowyer-Smyth!).
Improved: Optimized a portion of the rendering engine for newer CPU instruction sets (SSE2, SSSE3, AVX2). Depending on zoom level, CPU type, and other factors, rendering throughput has been improved by 10-50%.
Improved: Some performance optimizations for code that uses the indexers on the Surface class, which should improve effect plugin performance (thanks @Bruce Bowyer-Smyth!).
Fixed: Shortcut keys for the Adjustments menu weren't working until after you opened the menu for the first time.
Fixed: Canvas checkerboard, used to indicate transparent regions of the image, now scales with DPI.
Fixed some of the more rare cases of the SEHException/AccessViolationException crash caused by Direct2D.
Fixed: A bug in IndirectUI was resulting in a crash when using @BoltBait's Level Horizon plugin.
Fixed: Per-user fonts no longer cause a crash for the Store version.
New: The paintdotnet: protocol now works for the Classic version.
Fixed: The paintdotnet: protocol should now work properly with paths that have spaces in them.
Fixed: Hardened security for loading Custom Shape plugins via XAML (thanks @Bruce Bowyer-Smyth!).

Improved: Massive startup performance improvement when lots of effect plugins are installed.
Fixed a crash that would happen when closing an image, exiting the app, or sometimes just at random. This was happening due to a bug in Direct2D where ID2D1EffectContext does not honour the multithreaded initialization flag from its ID2D1Factory, and was thus corrupting its own internal data structures when released on the finalizer thread.
Fixed: DirectX 9 GPUs can now utilize hardware acceleration again (in 4.1.3 they were forced to use software rendering).
Fixed: The Black & White and Invert Colors adjustments no longer display an OK/Cancel dialogue.

Improved startup performance if "a lot" of effect plugins are installed. More optimizations are coming in the next update.
Fixed: Pixel grid no longer draws some dots darker than others at some zoom levels, as reported at https://forums.getpaint.net/topic/112794-pixel-grid-rendering-problems-when-zooming/
Fixed: Radial Blur was not handling alpha correctly
Fixed: IndirectUI ColorWheel swatch is now rendered correctly (without the fading alpha gradient)
Fixed: The tooltip describing the shortcut key for tools now indicates how many times to press the key (e.g., press S four times for Magic Wand selection)
Fixed: Pressing Escape to deselect now works with all tools (this bug was introduced in v4.0)
Fixed: Images with variable alpha were not displaying correctly at some zoom levels. They were "too dark" in translucent regions. Reported here: https://forums.getpaint.net/topic/112184-some-zoom-levels-display-alpha-as-extra-opaque/
Fixed: For the Store release, launching with the paintdotnet: protocol no longer shows an error if no parameters are provided (thanks @Bruce Bowyer-Smyth!)
Fixed a crash for some effects that were rendering too quickly
Fixed a bug in the Image>Resize dialog where the asterisk and the note about which resampling mode was being used, e.g. "* Bicubic will be used," weren't going away or updating correctly
New: Added a /set:SETTING=VALUE command-line parameter. This is specifically useful for disabling hardware acceleration if the app won't start or you can't reach the Settings dialog. This is also necessary for the Store release whose virtualized registry cannot be edited. To launch the Store version with hardware acceleration disabled, go to Start -> Run and type in "paintdotnet:/set:UI/EnableHardwareAcceleration=false" (without quotes) and press OK
New: Added detection for when "Diebold Warsaw" is causing Paint.NET to crash. The error message will indicate this cause.
Fixed: Addressed CVE-2018-18446. Credit goes to Bruce Bowyer-Smyth.
Fixed: Addressed CVE-2018-18447. Credit goes to Soroush Dalili from NCC Group.

This update converts some effects to use the GPU for rendering, resulting in huge performance gains. Copy/Paste can now be performed on selections, Bicubic resampling is now available for the Move Selected Pixels tool, and there are lots of little quality-of-life improvements and general bug fixes.

Improved: Gaussian Blur, Motion Blur, and Radial Blur now render using the GPU and are significantly faster.
Changed: The following effects are now rendered using the GPU: Edge Detect, Pixelate, and Relief.
Changed: The following adjustments are now rendered using the GPU: Black & White, Invert Colors.
New Effect: Distort -> Morphology (uses the GPU).
New Effect: Render -> Turbulence (uses the GPU).
New: Bicubic resampling is now supported for the Move Selected Pixels tool. A CPU with 6 or more cores is highly recommended if you want to make it the default mode from within Settings -> Tools.
New: Edit -> Copy Selection. This will copy the current selection's geometry to the clipboard as JSON text.
New: Edit -> Paste Selection. This will apply the selection from the clipboard to the current selection. All 5 selection combine modes are supported.
Changed: The Text tool now uses Points for font size measurement. You can also elect to use the old font size metric, "Fixed (96 DPI)" via the dropdown to the right of the font size.
Fixed: The Text tool's recentering algorithm when typing reaches the edge of the viewport should be better.
New: Added +/- buttons to the Tolerance and Hardness sliders.
Changed: Increased max zoom level to 6400%.
New: The mouse wheel may now be used to scroll a long menu, such as when a lot of effects are installed (thanks @toe_head2001!).
Changed: For Windows 7 SP1 users, the Platform Update from 2013 is now required (it contains Direct2D v1.1).
Fixed: The "Finish" button wasn't working if it was in an overflow container (thanks @toe_head2001!).
Fixed: Opening certain large images and then zooming with the mouse wheel would sometimes result in the scroll position being completely wrong.
Changed: Hiding a layer no longer auto-selects the nearest visible layer. You can re-enable this in Settings, although this setting may be removed in a future version.
New: For the Windows Store release, the paintdotnet: protocol can now be used to launch the app so that you can specify command-line parameters. For example, you can go to Start -> Run and type in paintdotnet:"path to file1.png" path_to_file_2.png then both images will be opened (even if Paint.NET is already open).
New: Added Heptagon (7-sided polygon) and Octagon (8-sided polygon) shapes.
Fixed the high-DPI inset-text scaling for the Shape selector (e.g. Pentagon with an inset "5").
New: Palettes are now also loaded from Documents/paint.net App Files/Palettes. This folder name is not localized so that installation scripts may easily make use of it.
Fixed: View -> Pixel Grid will now correctly adjust to dynamic changes in the theme (light vs. dark).
Fixed: The background color for the Tolerance slider has been corrected for non-dark themes.
Changed: Removed shortcut keys for all built-in Adjustments except for Invert Colors (Ctrl+Shift+I). This is being done to free up shortcut keys for other functionality.
New: Added a shortcut key to trigger a full .NET garbage collection: Ctrl+Alt+Shift+` (tick/tilde). This should only ever be needed for troubleshooting purposes.
New: Battery Saver Mode in Windows 10 is now respected, whether enabled manually or due to low battery. UI animations will be disabled.
New: Long file paths (>MAX_PATH) are now supported on Windows 10, as long as the group policy setting is enabled ("Enable Win32 long paths").
New for plugin developers: The IndirectUI Color Wheel control now supports an alpha slider. To use this, set the range (min/max values) of the Int32PropertyControl to [Int32.MinValue, Int32.MaxValue] (thanks @BoltBait!).
New for plugin developers: there is a new FileChooser property control type for string properties (thanks @toe_head2001!).
New for plugin developers: there is a new BinaryPixelOp.Apply(Surface, Surface, Surface, Rectangle) method overload (thanks @BoltBait!).
Changed: The IndirectUI text control now has a vertical scroll bar when multiline mode is enabled (thanks @toe_head2001!).
Changed: Visual C++ and OpenMP runtimes are now only loaded from the "app local" copy (never from the system directory). This fixes a number of headaches, and also works around a compatibility issue with the Surface Go.
Fixed: Crash when drag-and-dropping images onto Paint.NET when a tool was active but with uncommitted changes.
Fixed a very old and nasty crash, "InvalidOperationException: ScratchSurface already borrowed".

Fixed a bug where a pasted image would be clipped after choosing "Keep canvas size".

Paint.NET is free image and photo manipulation application for the Windows platform. Every feature of Paint.NET, including the user interface, was designed to be immediately intuitive and easy to learn without assistance.

Key Features Include:

• Special effects tools include: blurring, sharpening, red-eye removal, distortion, noise and embossing.

• 3D Rotate/Zoom effects make it very easy to add perspective and tilting.

• Image manipulation tools include: brightness, contrast, hue, saturation, curves, and levels. You can also convert an image to black and white, or sepia.

In order to navigate multiple images easily, Paint.NET uses a tabbed document interface. The tabs display a live thumbnail of the image instead of a text description.

Paint.NET uses a layers system to form the basis for rich image composition. Layers are likened to a stack of transparency slides that, when viewed together at the same time, form an image.

Added: "Fluid mouse input" option in Settings -> UI -> Troubleshooting. If you see major glitches while drawing, try disabling this.
Improved: Default brush size, font size, and corner radius size now scales with major DPI scaling levels (brush size of 2 at 100% scaling, brush size of 4 at 200% scaling, etc).
Improved: Default image size now scales with major DPI scaling levels (800x600 at 100%, 1600x1200 at 200%, etc.).
Improved performance and drawing latency by removing explicit calls to System.GC.Collect() except when low memory conditions are encountered.
Improved performance by greatly reducing object allocation amplification by reducing the concurrency level when using ConcurrentDictionary, and by removing Weak Reference allocations in favor of direct GCHandle usage.
Improved: Performance and battery usage by ensuring animations always run at the monitor's actual refresh rate.
Improved (reduced) CPU usage when moving the mouse around the canvas.
Removed: "Hold Ctrl to hide handle" from the Text tool because it was not useful and caused lots of confusion.
Fixed: Various high-DPI fixes, including horrible looking mouse cursors caused by a bug in the latest .NET WinForms update.
Fixed: Gradient tool no longer applies dithering "outside" of the gradient (in areas that should have a solid color).
Fixed: Very slow performance opening the Effects menu when lots of plugins are installed after installing the Windows 10 Creators Update.
Fixed: When cropping and then performing an undo, the scroll position was totally wrong.
Fixed a rendering glitch in the Save Configuration dialog (it would "wiggle").
Fixed: At certain brush sizes, the brush indicator on the canvas had a visual glitch in it due to a bug in Direct2D.
Fixed: Text tool buttons for Bold, Italics, Underline were not localized for a few languages.
Fixed a rare crash in the taskbar thumbnails.
Fixed: Drawing with an aliased brush and opaque color (alpha=255) sometimes resulted in non-opaque pixels due to a bug in Direct2D's ID2D1RenderTarget::FillOpacityMask.
Fixed: "Olden" effect should no longer cause crashes (it still has some rendering artifacts due to its multi threading problems, however).

Fixed very slow performance opening the Effects menu when lots of plugins are installed after installing the Windows 10 Creators Update.
Fixed: Gradient tool no longer applies dithering "outside" of the gradient (in areas that should have a solid color).
Added: "Fluid mouse input" option in Settings -> UI -> Troubleshooting. If you see major glitches while drawing, try disabling this.
Fixed: When cropping and then performing an undo, the scroll position was totally wrong.
Fixed a rendering glitch in the Save Configuration dialog (things would "wiggle").
Improved: Default brush size, font size, and corner radius size now scales with major DPI scaling levels (brush size of 2 at 100% scaling, brush size of 4 at 200% scaling, etc).
Improved: Default image size now scales with major DPI scaling levels (800x600 at 100%, 1600x1200 at 200%, etc.).
Improved: Removed "hold Ctrl to hide handle" from the Text tool because it was not useful and caused lots of confusion.
Improved performance and drawing latency by removing explicit calls to System.GC.Collect() except when low memory conditions are encountered.
Improved performance by greatly reducing object allocation amplification by reducing the concurrency level when using ConcurrentDictionary, and by removing WeakReference allocations in favor of direct GCHandle usage.
Improved (reduced) CPU usage when moving the mouse around the canvas.
Fixed: At certain brush sizes, the brush indicator on the canvas had a visual glitch in it due to a bug in Direct2D.
Fixed: Text tool buttons for Bold, Italics, Underline were not localized for a few languages.
Fixed: Various high-DPI fixes, including horrible looking mouse cursors caused by a bug in the latest .NET WinForms update.
Fixed a rare crash in the taskbar thumbnails.
Fixed: Drawing with an aliased brush and opaque color (alpha=255) sometimes resulted in non-opaque pixels due to a bug in Direct2D's ID2D1RenderTarget::FillOpacityMask.
Fixed: "Olden" effect should no longer cause crashes (it still has some rendering artifacts due to its multithreading problems, however).
New: Portable mode can be enabled via a setting in the .exe.config, which will redirect app settings into a local JSON file (see blog/forum post for details).

Fixed a crash or hang that sometimes happens when copying images from Internet Explorer, Edge, or Firefox, and then using File->New or Edit->Paste in paint.net.

Fixed a crash in the Magic Wand tool if it was used twice in a row with a selection mode other than Replace.

- Fixed "Missing api-ms-win-core-timezone-l1-1-0.dll" error that was being seen on some Windows 7 systems due to partial install or uninstall of Microsoft's Universal C Runtime.
- Fixed the layout for the File->New, Image->Resize, and Image->Canvas Size dialogs in all known situations (various languages, DPI sizes, font configurations).
- Fixed: Old versions of PSD plugin couldn't load due to removal of PrivateThreadPool
- Fixed a crash when typing a negative number for a zoom level.