InitAlpha Property

Summary

Indicates whether to initialize the alpha channel when loading images as 32 or 64-bit.

Syntax

Objective-C

C++/CLI

Java

Python

public bool InitAlpha { get; set; }

@property (nonatomic, assign) BOOL initAlpha;

public boolean getInitAlpha() 
public void setInitAlpha(boolean value)

public: 
property bool InitAlpha { 
   bool get(); 
   void set (    bool ); 
}

InitAlpha # get and set (CodecsLoadOptions)

Property Value

Value	Description
true	To set the alpha channel to ones (0xFF for 8-bit and OxFFFF for 16-bit). true is the default value.
false	To retain the alpha channel values from the original bitmap.

Remarks

The default value for this property is true.

When loading 32-bit or 64-bit images that are known to have valid alpha channel information, you should set this property to false if you wish to retain the alpha channel in the loaded image.

The following formats will ignore this option, and will always retain alpha channel information during load:

Example

using Leadtools; 
using Leadtools.Codecs; 
 
using Leadtools.ImageProcessing.Core; 
 
 
RasterImage image; 
private void Codecs_LoadImage(object sender, CodecsLoadImageEventArgs e) 
{ 
   //copy each row of data into our manually allocated RasterImage 
   image.SetRow(e.Row, e.Buffer.Data, image.BytesPerLine * e.Lines); 
} 
 
public void AllocateImageExample() 
{ 
   string fileName = Path.Combine(LEAD_VARS.ImagesDir, "image1.cmp"); 
   RasterCodecs codecs = new RasterCodecs(); 
   CodecsImageInfo info = codecs.GetInformation(fileName, false); 
   int size = info.Width * info.Height * info.BitsPerPixel; 
   IntPtr data = Marshal.AllocHGlobal(size); 
 
   image = new RasterImage(RasterMemoryFlags.User, info.Width, info.Height, info.BitsPerPixel, RasterByteOrder.Bgr, info.ViewPerspective, null, data, size); 
   image.Access(); 
   //Setting the loading options. 
   //Do NOT allow LEADTOOLS to allocate the image data 
   codecs.Options.Load.AllocateImage = false; // CodecsOptions & CodecsLoadOptions reference 
   codecs.Options.Load.StoreDataInImage = false; 
   //keeping the loaded image data compressed in memory. 
   codecs.Options.Load.Compressed = true; 
   codecs.Options.Load.DiskMemory = false; 
   //force a palletized image to be dithered to the LEAD fixed palette. 
   codecs.Options.Load.FixedPalette = true; 
   //we know the format of the file 
   codecs.Options.Load.Format = RasterImageFormat.Cmp; 
   //disable loading metadata markers if present in the file, false to ignore them. 
   codecs.Options.Load.Markers = false; 
   codecs.Options.Load.NoDiskMemory = true; 
   codecs.Options.Load.NoInterlace = false; 
   codecs.Options.Load.NoTiledMemory = true; 
   codecs.Options.Load.Passes = 0; 
   //ignore the view perspective stored in the file. 
   codecs.Options.Load.Rotated = false; 
   //set negative pixel values to 0. 
   codecs.Options.Load.Signed = false; 
   codecs.Options.Load.InitAlpha = true; 
   //load super-compressed in memory 
   codecs.Options.Load.SuperCompressed = true; 
   codecs.Options.Load.TiledMemory = false; 
   codecs.Options.Load.XResolution = 350; 
   codecs.Options.Load.YResolution = 350; 
   //allow loading corrupted images 
   codecs.Options.Load.LoadCorrupted = true; 
 
   codecs.LoadImage += Codecs_LoadImage; 
   codecs.Load(fileName); 
   codecs.LoadImage -= Codecs_LoadImage; 
   image.Release(); 
 
   //Meta file's comments will be saved. 
   //CodecsSaveOptions reference 
   codecs.Options.Save.Comments = true; 
   codecs.Options.Save.FixedPalette = true; 
   codecs.Options.Save.GeoKeys = false; 
   //Tiff file output will be gray. 
   codecs.Options.Save.GrayOutput = true; 
   //Meta file's markers will be saved. 
   codecs.Options.Save.Markers = true; 
   codecs.Options.Save.MotorolaOrder = false; 
   codecs.Options.Save.OptimizedPalette = true; 
   codecs.Options.Save.Password = "LEADTOOLS"; 
 
   LeadSize[] resolutions = new LeadSize[1]; 
   resolutions[0].Width = 350; 
   resolutions[0].Height = 350; 
 
   codecs.Options.Save.GetResolutions(); 
   codecs.Options.Save.SetResolutions(resolutions); 
   codecs.Options.Save.Reset(); 
 
   //Meta file's tags will be saved. 
   codecs.Options.Save.Tags = true; 
   codecs.Options.Save.UseImageDitheringMethod = true; 
 
 
 
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "allocate_image.tif"), RasterImageFormat.Tif, 8, 1, image.PageCount, 1, CodecsSavePageMode.Overwrite); 
 
   // Finalize cannot be called directly, it is invoked automatically. 
   // To clean up before exiting, use Dispose 
   image.Dispose(); 
   Marshal.FreeHGlobal(data); 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

CodecsLoadOptions Class

CodecsLoadOptions Members

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Help Version 22.0.2023.5.5

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