C#
C++/CLI
Python
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public static void PaintCmykPlanes(RasterImage image,IntPtr hdc,LeadRect srcRect,LeadRect srcClipRect,LeadRect destRect,LeadRect destClipRect,RasterPaintProperties properties,object colorConverter)
image
The source image.
hdc
The destination Windows device context handle where the CMYK planes will be displayed.
srcRect
A Leadtools.LeadRect object that specifies the part of the image to use as the display source.
The coordinates in the srcRect rectangle are relative to the image. You can pass Rectangle.Empty to use the default, which matches the image.
srcClipRect
A Leadtools.LeadRect object specifies the portion of the display source to paint. Generally, this is used for updating the display when part of the source image has changed.
The coordinates in the srcClipRect rectangle are relative to the image. You can pass Rectangle.Empty to use the default, which matches the image
destRect
A Leadtools.LeadRect object that determines how the source rectangle is scaled and how the image is positioned in the destination hdc handle.
The coordinates in the destRect object are relative to the hdc handle. There is no default for this parameter. You must specify the Leadtools.LeadRect object.
destClipRect
A Leadtools.LeadRect object that specifies the portion of the display rectangle to paint. Generally, this is used for updating changes in the display surface, such as when a user moves another window, uncovering a part of the image that had been covered up.
The coordinates in the destClipRect are relative to the device context handle. You can pass Rectangle.Empty to use the default, which matches the device context handle. In most cases, however, you should use the rectangle returned by the .NET PaintEventArgs.ClipRectangle or Windows WM_PAINT message.
properties
Options for the display.
colorConverter
Optional RasterColorConverter object used to convert CMYK data to BGR during painting. Pass null (Nothing in VB) to let LEADTOOLS use the built-in color conversion functions.
The image must contain pages that represent each of the CMYK planes.
The data is automatically converted to BGR and dithered (if necessary) without affecting the original data in the image.
The image planes are typically created using RasterCodecs.LoadCmykPlanes.
Windows can only paint BGR data. Therefore, we need to convert CMYK data to BGR during the painting process. You will notice that the painting of regular images (which are already BGR) is faster than the painting of CMYK planes.
The color conversion can be performed using RasterColorConverter.
These conversions are accurate, but are slower than the built-in CMYK->RGB conversion formulas. To use the accurate conversions, create a RasterColorConverter object and pass it as colorConverter. To use the fast conversions, pass null (Nothing for VB) for colorConverter.
Note that there is a visible difference between using a RasterColorConverter object or not. Also, make sure you create a correct CMYK->BGR RasterColorConverter object.
If destRect is larger or smaller than the image's actual dimensions, then the image will be scaled to fit destRect.
For more information, refer to the following:
using Leadtools;using Leadtools.Codecs;using Leadtools.Drawing;using Leadtools.ImageProcessing;public void PaintCmykPlanesExample(){PaintCmykPlanesForm f = new PaintCmykPlanesForm();f.ShowDialog();}class PaintCmykPlanesForm : Form{private RasterImage image;public PaintCmykPlanesForm(){// Load the cmyk planesRasterCodecs codecs = new RasterCodecs();string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, @"ET\src_cmyk_image.tif");image = codecs.LoadCmykPlanes(srcFileName, 0, 1);Text = "PaintCmykPlanes Example";}protected override void Dispose(bool disposing){// Clean upif (disposing){image.Dispose();}base.Dispose(disposing);}protected override void OnPaint(PaintEventArgs e){// Draw the image fit and center on this formLeadRect destRect = LeadRect.FromLTRB(ClientRectangle.Left, ClientRectangle.Top, ClientRectangle.Right, ClientRectangle.Bottom);destRect = RasterImage.CalculatePaintModeRectangle(image.ImageWidth,image.ImageHeight,destRect,RasterPaintSizeMode.Fit,RasterPaintAlignMode.Center,RasterPaintAlignMode.Center);RasterPaintProperties props = RasterPaintProperties.Default;props.UsePaintPalette = true;RasterImagePainter.PaintCmykPlanes(image, e.Graphics, LeadRect.Empty, LeadRect.Empty, destRect, LeadRect.Empty, props, null);base.OnPaint(e);}}static class LEAD_VARS{public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images";}