CompressRows(ushort[],byte[],long,int,int) Method

Summary

Performs buffer-to-buffer RLE compression of 1-bit image data

Syntax

C++/CLI

Python

[CLSCompliantAttribute(false)] 
public static void CompressRows( 
   ushort[] runBuffer, 
   byte[] buffer, 
   long bufferOffset, 
   int width, 
   int rows 
)

[CLSCompliantAttribute(false)] 
public: 
static void CompressRows(  
   array<ushort>^ runBuffer, 
   array<byte>^ buffer, 
   long bufferOffset, 
   int width, 
   int rows 
)

def CompressRows(self,runBuffer,buffer,bufferOffset,width,rows):

Parameters

runBuffer
The output buffer, which will be filled with 1-bit compressed image data.

buffer
The input buffer, which contains the 1-bit image data to be compressed.

bufferOffset
Zero-based index into buffer.

width
The number of pixels to process.

rows
The number of rows to process.

Remarks

Use this method to process multiple lines of image data. This method is available in the Document/Medical Toolkits.

This function is useful for working with 1-bit images that are loaded in their compressed formats for faster loading and display. For more information, refer to Speeding Up 1-Bit Documents.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Dicom; 
using Leadtools.Drawing; 
using Leadtools.Controls; 
using Leadtools.Svg; 
 
 
public void GetRowCompressedExample() 
{ 
	RasterCodecs codecs = new RasterCodecs(); 
	// Load the bitmap, at 1 bit per pixel, compressed 
	codecs.Options.Load.Compressed = true; 
	RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "OCR1.TIF"), 1, Leadtools.Codecs.CodecsLoadByteOrder.Bgr, 1, 1); 
 
	// This example does not work with rotated view perspectives. 
	if ((image.ViewPerspective != RasterViewPerspective.TopLeft) || (image.ViewPerspective != RasterViewPerspective.BottomLeft)) 
		image.ChangeViewPerspective(RasterViewPerspective.TopLeft); 
 
	// Adjust the YOffset if the view perspective is bottom left. 
	int nRow = 500; // first row to get. 
	int nYSize = 500; // number of rows to get. 
 
	if (image.ViewPerspective == RasterViewPerspective.BottomLeft) 
		nRow = image.Height - nRow - nYSize; 
 
	// Allocate the buffers. 
	byte[] pBuffer = new byte[Convert.ToInt32((((image.Width + 31) & ~(31)) / 8)) * nYSize]; // Buffer to hold the expanded row. 
	ushort[] pRunBuffer = new ushort[((image.Width + 3) * 2) * nYSize]; // Buffer to hold the compressed row. 
 
	if (image.IsGlobalMemory) 
		image.Access(); 
	// Get the top nRow lines. 
	image.GetRowCompressed(null, pRunBuffer, 0, nRow, nYSize); 
	// Expand the compressed data. 
	RasterRleCompressor.ExpandRows(pRunBuffer, pBuffer, 0, image.Width, nYSize); 
	// Invert the data. 
 
	for (int n = 0; n < (image.BytesPerLine * nYSize); n++) 
		pBuffer[n] ^= 0xff; 
 
 
	// Compress the inverted data. 
	RasterRleCompressor.CompressRows(pRunBuffer, pBuffer, 0, image.Width, nYSize); 
 
	// Put the inverted, compressed data back into the image. 
	image.SetRowCompressed(null, pRunBuffer, 0, nRow, nYSize); 
 
	if (image.IsGlobalMemory) 
		image.Release(); 
 
	codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_getrowcompresed.BMP"), RasterImageFormat.Bmp, 0); 
 
	image.Dispose(); 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

RasterRleCompressor Class

RasterRleCompressor Members

Overload List

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Help Version 22.0.2023.5.16

Leadtools Assembly

Introduction

Getting Started

Namespaces

Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies