RotateCommand Class

Summary

Rotates an image by the number of degrees specified.

Syntax

Objective-C

C++

Java

public class RotateCommand : RasterCommand

Public Class RotateCommand  
   Inherits RasterCommand

@interface LTRotateCommand : LTRasterCommand

public class RotateCommand extends RasterCommand

public ref class RotateCommand : public RasterCommand

Remarks

This command has the following features:

It uses the center of the image as the center of rotation.
It can rotate the image clockwise or counterclockwise up to 360 degrees in 100th-degree increments.
It can resize the image to accommodate the rotated height and width, or it can retain the original height and width, cropping the image as necessary.
It uses FillColor as the background color to fill any new area created by the rotation.

RotateCommandFlags.Resample and RotateCommandFlags.Bicubic can be combined with RotateCommandFlags.Resize, but they can not be combined with each other.

If RotateCommandFlags.Resize is set, then the image is resized. Otherwise, the image is cropped.

Interpolation can be done while rotating certain images. This produces superior output, eliminating the jaggedness occurring when rotating images at angles that are not multiples of 90. (ie when RotateCommand.Angle is not a multiple of 9000).

The only images that are interpolated are:

8-bit grayscale images (for best results, all gray values should be in the image palette). If the rotation does not give the expected results, you can use GrayscaleCommand with GrayscaleCommand.BitsPerPixel = 8 to change the image into a proper grayscale image.
12-bit and 16-bit grayscale images that do not have a palette. Grayscale image can have a palette if they have been loaded from certain DICOM images or if the WindowLevelCommand has been used. Use GrayscaleCommand with GrayscaleCommand.BitsPerPixel = 12 or GrayscaleCommand with GrayscaleCommand.BitsPerPixel = 16 if RotateCommand does not seem to do any interpolation during the rotation.
16-bit color images
24-bit, 32-bit, 48-bit and 64-bit color images

For all other images, RotateCommand ignores the resampling flags and the rotate is performed without interpolation.

For more information, refer to Processing an Image.

Example

This example will load an image, rotate it by 45 degrees and then save it back to disk

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
 
 
public void RotateCommandExample() 
{ 
	RasterCodecs codecs = new RasterCodecs(); 
 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "RotateCommand.bmp"); 
 
	// Load the source image from disk 
	RasterImage image = codecs.Load(srcFileName); 
 
	// Rotate the image by 45 degrees 
	RotateCommand command = new RotateCommand(); 
	command.Angle = 45 * 100; 
	command.FillColor = new RasterColor(255, 255, 255); 
	command.Flags = RotateCommandFlags.Bicubic; 
	command.Run(image); 
 
	// Save it to disk 
	codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24); 
 
	// Clean Up 
	image.Dispose(); 
	codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
 
Public Sub RotateCommandExample() 
   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, "RotateCommand.bmp") 
 
   ' Load the source image from disk 
   Dim image As RasterImage = codecs.Load(srcFileName) 
 
   ' Rotate the image by 45 degrees 
   Dim command As RotateCommand = New RotateCommand() 
   command.Angle = 45 * 100 
   command.FillColor = New RasterColor(255, 255, 255) 
   command.Flags = RotateCommandFlags.Bicubic 
   command.Run(image) 
 
   ' Save it to disk 
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24) 
 
   ' Clean Up 
   image.Dispose() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

RotateCommand Members

Leadtools.ImageProcessing Namespace

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Help Version 21.0.2021.7.2

Leadtools Assembly

Introduction

Getting Started

Namespaces

Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies