GetRegionClipSegments Method

Summary

Gets the segments contained in the region for a particular row.

Syntax

Objective-C

C++

Java

public int GetRegionClipSegments( 
   int row, 
   int[] segmentsBuffer, 
   int segmentsBufferOffset 
)

Public Function GetRegionClipSegments( _ 
   ByVal row As Integer, _ 
   ByVal segmentsBuffer() As Integer, _ 
   ByVal segmentsBufferOffset As Integer _ 
) As Integer

- (NSUInteger)regionClipSegmentsForRow:(NSInteger)row  
                        segmentsBuffer:(unsigned int *)buffer

public int getRegionClipSegments( 
  int row,  
  int[] segmentsBuffer,  
  int segmentsBufferOffset 
)

public: 
int GetRegionClipSegments(  
   int row, 
   array<int>^ segmentsBuffer, 
   int segmentsBufferOffset 
)

Parameters

row
The number of the row for which to get the segments. The first row is 0, and the last row is 1 less than the image height.

segmentsBuffer
Buffer to be updated with the segments from row contained in the region.

segmentsBufferOffset
Zero based index into segmentsBuffer.

Return Value

The number of segments from row that are contained in the region.

Remarks

To use this method, first call GetRegionBounds with the xform set to null, to get the image boundaries. The bounding rectangle will indicate which rows are contained in the region. Go through all the rows contained in the region to get the segments contained in the region.

The segments are returned as an array of pairs of horizontal offsets. The first point in the pair is the beginning of the segment (it is contained in the region). The last point in the pair is the end of the segment. To follow the Windows rules, the end of the segment is the first point NOT CONTAINED in the region.

In most regions, there will be one segment per row. However, some regions can have 0, 1, 2 or more segments.

For example, assume that for a particular row there are two segments. segmentsBuffer will be filled with 4 values. Let's call them x0, x1, x2, x3. In this case:

portion from 0 to x0 - 1 is OUTSIDE the region
portion from x0 to x1 - 1 is INSIDE the region
portion from x1 to x2 - 1 is OUTSIDE the region
portion from x2 to x3 - 1 is INSIDE the region
portion from x3 to Width - 1 is OUTSIDE the region

Example

This example sets the value of pixels inside a region to half intensity.

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 GetRegionClipSegmentsExample() 
{ 
	RasterCodecs codecs = new RasterCodecs(); 
 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_GetRegionClipSegments.bmp"); 
 
	// Load the image 
	RasterImage image = codecs.Load(srcFileName); 
 
	// Add a region to the image 
	LeadRect rc = new LeadRect(image.Width / 3, image.Height / 3, image.Width / 3, image.Height / 3); 
	image.AddEllipseToRegion(null, rc, RasterRegionCombineMode.Set); 
 
	// Set the pixels inside the region to black 
 
	// Get the maximum number of elements in a row, 
	// so we know how big the array of segments should be 
	int maxClipSegments = image.CalculateRegionMaximumClipSegments(); 
 
	// Get the region bounds, so we know which is the first row 
	LeadRect rgnBounds = image.GetRegionBounds(null); 
 
	// Allocate an array large enough to store the maximum number of segments. 
	int[] segmentBuffer = new int[maxClipSegments]; 
 
	// Loop through the region rows 
	for (int y = rgnBounds.Top; y < rgnBounds.Bottom; y++) 
	{ 
		// Get the segments for the row 
		image.GetRegionClipSegments(y, segmentBuffer, 0); 
 
		// Do something with the pixels 
		for (int i = 0; i < maxClipSegments / 2; i++) 
		{ 
			for (int j = segmentBuffer[i]; j < segmentBuffer[i + 1]; j++) 
			{ 
				RasterColor clr = image.GetPixelColor(y, j); 
				clr = new RasterColor(clr.R / 2, clr.G / 2, clr.B / 2); 
				image.SetPixelColor(y, j, clr); 
			} 
		} 
	} 
 
	// Save the image back to file 
	codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24); 
 
	image.Dispose(); 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Core 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Controls 
Imports Leadtools.Dicom 
Imports Leadtools.Drawing 
Imports Leadtools.Svg 
 
Public Sub GetRegionClipSegmentsExample() 
   Dim codecs As RasterCodecs = New RasterCodecs() 
 
   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_GetRegionClipSegments.bmp") 
 
   ' Load the image 
   Dim image As RasterImage = codecs.Load(srcFileName) 
 
   ' Add a region to the image 
   Dim rc As LeadRect = New LeadRect(image.Width \ 3, image.Height \ 3, image.Width \ 3, image.Height \ 3) 
   image.AddEllipseToRegion(Nothing, rc, RasterRegionCombineMode.Set) 
 
   ' Set the pixels inside the region to black 
 
   ' Get the maximum number of elements in a row, 
   ' so we know how big the array of segments should be 
   Dim maxClipSegments As Integer = image.CalculateRegionMaximumClipSegments() 
 
   ' Get the region bounds, so we know which is the first row 
   Dim rgnBounds As LeadRect = image.GetRegionBounds(Nothing) 
 
   ' Allocate an array large enough to store the maximum number of segments. 
   Dim segmentBuffer As Integer() = New Integer(maxClipSegments - 1) {} 
 
   ' Loop through the region rows 
   Dim y As Integer = rgnBounds.Top 
   Do While y < rgnBounds.Bottom 
      ' Get the segments for the row 
      image.GetRegionClipSegments(y, segmentBuffer, 0) 
 
      ' Do something with the pixels 
      Dim i As Integer = 0 
      Do While i < maxClipSegments / 2 
         Dim j As Integer = segmentBuffer(i) 
         Do While j < segmentBuffer(i + 1) 
            Dim clr As RasterColor = image.GetPixelColor(y, j) 
            clr = New RasterColor(clr.R \ 2, clr.G \ 2, clr.B \ 2) 
            image.SetPixelColor(y, j, clr) 
            j += 1 
         Loop 
         i += 1 
      Loop 
      y += 1 
   Loop 
 
   ' Save the image back to file 
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24) 
 
   image.Dispose() 
   codecs.Dispose() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

RasterImage Class

RasterImage Members

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Help Version 21.0.2021.7.2

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