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IsVisible Method

Summary

Tests whether the specified LeadPoint structure is contained within this RasterRegion.

Syntax

C#
VB
Java
Objective-C
WinRT C#
C++
public bool IsVisible( 
   LeadPoint point 
) 
Public Function IsVisible( _ 
   ByVal point As Leadtools.LeadPoint _ 
) As Boolean 
public bool IsVisible(  
   Leadtools.LeadPoint point 
) 
- (BOOL)isVisible:(LeadPoint)point 
public boolean isVisible(LeadPoint point) 
 function Leadtools.RasterRegion.IsVisible(  
   point  
) 
public: 
bool IsVisible(  
   Leadtools.LeadPoint point 
)  

Parameters

point
The LeadPoint structure to test.

Return Value

true when point is contained within this RasterRegion; false, otherwise.

Example

This example will create a small elliptical region in an image, gets the RasterRegion object before resetting the image region. It will then switch the red and blue component of every pixel inside the region data.

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using LeadtoolsExamples.Common; 
 
public void RasterRegionIsVisibleExample() 
{ 
   string srcFileName = Path.Combine(ImagesPath.Path, "Image1.cmp"); 
   string destFileName = Path.Combine(ImagesPath.Path, "Image1_IsVisibleRegion.bmp"); 
 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      // Load the source image 
      using (RasterImage image = codecs.Load(srcFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
      { 
         // Add a small elliptical region 
         image.AddEllipseToRegion(null, new LeadRect(image.ImageWidth / 3, image.ImageHeight / 3, image.ImageWidth / 3, image.ImageHeight / 3), RasterRegionCombineMode.Set); 
 
         // Get the region 
         using (RasterRegion region = image.GetRegion(null)) 
         { 
            // Remove the region from the image 
            image.MakeRegionEmpty(); 
 
            // Loop the image pixels, if it is inside the region, switch 
            // the red and blue component of the pixel color 
            for (int y = 0; y < image.Height; y++) 
            { 
               for (int x = 0; x < image.Width; x++) 
               { 
                  // Check if this pixel is inside the region 
                  if (region.IsVisible(new LeadPoint(x, y))) 
                  { 
                     // Yes, flip its R and B component 
                     RasterColor color = image.GetPixelColor(y, x); 
                     color = new RasterColor(color.B, color.G, color.R); 
                     image.SetPixelColor(y, x, color); 
                  } 
               } 
            } 
         } 
         codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24); 
      } 
   } 
} 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
 
Public Sub RasterRegionIsVisibleExample() 
   Dim codecs As New RasterCodecs() 
 
   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_IsVisibleRegion.bmp") 
 
   ' Load the source image 
   Using image As RasterImage = codecs.Load(srcFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1) 
      ' Add a small elliptical region 
      image.AddEllipseToRegion(Nothing, New LeadRect(image.ImageWidth \ 3, image.ImageHeight \ 3, image.ImageWidth \ 3, image.ImageHeight \ 3), RasterRegionCombineMode.Set) 
 
      ' Get the region 
      Using region As RasterRegion = image.GetRegion(Nothing) 
         ' Remove the region from the image 
         image.MakeRegionEmpty() 
 
         ' Loop the image pixels, if it is inside the region, switch 
         ' the red and blue component of the pixel color 
         For y As Integer = 0 To image.Height - 1 
            For x As Integer = 0 To image.Width - 1 
               ' Check if this pixel is inside the region 
               If (region.IsVisible(New LeadPoint(x, y))) Then 
                  ' Yes, flip its R and B component 
                  Dim color As RasterColor = image.GetPixelColor(y, x) 
                  color = New RasterColor(color.B, color.G, color.R) 
                  image.SetPixelColor(y, x, color) 
               End If 
            Next 
         Next 
      End Using 
 
      codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24) 
   End Using 
 
   codecs.Dispose() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class 

Requirements

Target Platforms

Help Version 19.0.2017.10.19
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Leadtools Assembly