NOTE: This would require XP or later or bundeling the gdiplus.dll in your installer. SmoothingModeHighQuality = QualityModeHigh InterpolationModeHighQualityBilinear = 6 Īnd smooting mode: SmoothingModeDefault = QualityModeDefault InterpolationModeHighQuality = QualityModeHigh InterpolationModeLowQuality = QualityModeLow

You can choose the quality VS speed factor by changing the interpolation mode InterpolationModeDefault = QualityModeDefault If Canvas is TGPGraphics, Bounds is TGPRectF and NewImage is TGPImage instance: Canvas.SetInterpolationMode(InterpolationModeHighQualityBicubic) Ĭanvas.SetSmoothingMode(SmoothingModeHighQuality) Ĭanvas.DrawImage(NewImage, Bounds, 0, 0, NewImage.GetWidth, NewImage.GetHeight, UnitPixel) not calling inherited use GDIPOB.pas's TGPGraphics class Procedure TBitmapForceHalftone.Draw(ACanvas: TCanvas const Rect: TRect) Procedure Draw(ACanvas: TCanvas const Rect: TRect) override So I 'fixed' it with assigning to one of these instead: TBitmapForceHalftone=class(TBitmap)

As Rob points out, TBitmap.Draw uses HALFTONE only when the destination canvas is 8 bits-per-pixel or lower and the source canvas has more. Update (2014-09) Just now I was in a similar situation (again) and had a TImage in a TScrollBox with lots more going on on the form, and really wanted Image1.Stretch:=true to do halftone.

I'm not sure if this is provided using default Delphi calls, but that's the way I generally solve this issue. However, if you wish to express your appreciation for the time and energy spend on developing, documenting, supporting and maintaining Graphics32, the team accepts with gratitude any donation made. If you revert to using Win32 API calls, you can use SetStretchBltMode to HALFTONE and use StretchBlt. Graphics32 is free under the terms of the Mozilla Public License.

Graphics32 vs imageen