LoadCmykPlanes(Stream,int,int) Method

Summary

Loads CMYK, TIFF or JPEG streams as CMYK and avoids the colorspace conversion to RGB.

Syntax

Objective-C

C++/CLI

Java

Python

public RasterImage LoadCmykPlanes( 
   Stream stream, 
   int bitsPerPixel, 
   int pageNumber 
)

- (nullable LTRasterImage *)loadCmykPlanesFromStream:(LTLeadStream *)stream  
                                        bitsPerPixel:(NSInteger)bitsPerPixel  
                                          pageNumber:(NSInteger)pageNumber  
                                               error:(NSError **)error

public RasterImage loadCmykPlanes(ILeadStream stream, int bitsPerPixel, int pageNumber)

public: 
RasterImage^ LoadCmykPlanes(  
   Stream^ stream, 
   int bitsPerPixel, 
   int pageNumber 
)

def LoadCmykPlanes(self,stream,bitsPerPixel,pageNumber):

Parameters

stream
A Stream containing the data of the image file to load. The image data must be CMYK; otherwise, the method will fail and throw an exception.

bitsPerPixel
Resulting image pixel depth. Possible values are:

Value	Meaning
0	Each plane will have the same bits/pixel as the source file (8 or 16).
8	Each plane will be a grayscale 8 bits per pixel image.
16	Each plane will be a grayscale 16 bits per pixel image. This is not available for saving JPEG CMYK files.

pageNumber
1-based index of the page from which the planes should be loaded.

Return Value

A RasterImage that this method loads. The image will contain one page for each of the CMYK planes.

Remarks

If the data does not have to be loaded as CMYK, use Load or LoadAsync.

Support for 16-bit grayscale images is only available in the Document/Medical Imaging editions.

This method will fail if the input file is not TIFF or JPEG CMYK. Note that not all the pages have to be CMYK - it is enough if only the page that you wish to load is CMYK.

Only the following memory load options are supported by this method:

This method uses the values of RasterCodecs.Options.Tiff.Load.ImageFileDirectoryOffset.

If the image being loaded contains alpha channel information, the alpha channel(s) will be loaded as well. First alpha channel will be stored as page 5, second alpha as plane 6, etc.

Use RasterImagePainter.PaintCmykPlanes to display the array and SaveCmykPlanes to save an image as a CMYK TIFF or JPEG file.

If you want to convert the CMYK array to a regular BGR image and use the other methods or save to a file format other than TIFF CMYK, use ColorMergeCommand and set the ColorMergeCommand.Type to ColorMergeCommandType.Cmyk.

If you have an alpha image, use RasterImage.SetAlphaImage to set the alpha image.

You can apply image processing on each individual image. This allows you to process each color plane separately.

If you want to load a non-CMYK file as an array of color planes, use the normal Load or LoadAsync methods and then use the ColorSeparateCommand and RasterImage.CreateAlphaImage methods.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
void CmykPlanesExample(string cmykTifFile) 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "CmykPlanesTif.tif"); 
 
   // Load the CMYK Planes of this image 
   RasterImage cmykImage = codecs.LoadCmykPlanes(cmykTifFile, 8, 1); 
 
   Debug.WriteLine("CMYK planes loaded into an image with {0} pages", cmykImage.PageCount); 
   Debug.Assert(cmykImage.PageCount == 4); 
 
   // The load has succeeded. Increase the brightness of the K (black) plane by 50% 
   // Note that this will DARKEN the image, because we increased the amount of black! 
 
   Debug.WriteLine("Changing the intensity of the K plane (the 4th page)"); 
   ChangeIntensityCommand command = new ChangeIntensityCommand(); 
   command.Brightness = 500; 
   cmykImage.Page = 4; 
   command.Run(cmykImage); 
   cmykImage.Page = 1; 
 
   Debug.WriteLine("Saving the image to the destination file"); 
   codecs.SaveCmykPlanes(cmykImage, destFileName, RasterImageFormat.TifLzwCmyk, 8, 1, CodecsSavePageMode.Overwrite); 
   cmykImage.Dispose(); 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

RasterCodecs Class

RasterCodecs Members

Overload List

Handling CMYK Files as Separate Images

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Help Version 22.0.2023.5.5

Leadtools.Codecs Assembly

Introduction

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Namespaces

Leadtools.Codecs Namespace

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