Load and Save Images - Java

This tutorial shows how to use the LEADTOOLS SDK to create a Java application that loads and saves an image.

Overview  
Summary This tutorial covers how to load and save an image in a Java application.
Completion Time 30 minutes
Project Download tutorial project (2 KB)
Platform Java Application
IDE Eclipse
Runtime License Download LEADTOOLS
Try it in another language

Required Knowledge

Before working on the Load and Save an Image - Java tutorial, get familiar with the basic steps of creating a project by reviewing the Add References and Set a License tutorial.

Create the Project and Add LEADTOOLS References

Start with a copy of the project created in the Add References and Set a License tutorial. If that project is unavailable, follow the steps in that tutorial to create it.

The references needed depend upon the purpose of the project. The following JAR files are needed for this tutorial:

The JAR files are located at <INSTALL_DIR>\LEADTOOLS22\Bin\Java

For a complete list of which JAR files are required for your application, refer to Files to be Included with your Java Application.

Set the License File

The License unlocks the features needed for the project. It must be set before any toolkit function is called. For details including tutorials for different platforms, refer to Setting a Runtime License.

There are two types of runtime licenses:

Note

Adding LEADTOOLS references and setting a license are covered in more detail in the Add References and Set a License tutorial.

Add the Load Image Code

With the project created, the references added, and the license set, coding can begin.

In the Package Explorer, open the _Main.java class. Add two new methods to the _Main class called LoadImage(String filename, RasterCodecs codecs) and SaveImage(RasterImage _image, String outputFile, RasterCodecs _codecs). call these methods inside the run() method after the SetLicense() call, putting the load call first.

Add the following import statements to the import block at the top.

Java
import java.io.*; 
import java.nio.file.Files; 
import java.nio.file.Paths; 
 
import leadtools.*; 
import leadtools.codecs.*; 
Java
public static void main(String[] args) throws IOException 
{ 
	new _Main().run(args); 
} 
private void run(String[] args) { 
	try { 
		Platform.setLibPath("C:\\LEADTOOLS22\\Bin\\CDLL\\x64"); 
		Platform.loadLibrary(LTLibrary.LEADTOOLS); 
		Platform.loadLibrary(LTLibrary.CODECS); 
			 
		SetLicense(); 
			 
		RasterCodecs codecs = new RasterCodecs(); 
		String inputFile = "C:\\LEADTOOLS22\\Resources\\Images\\image1.cmp"; 
		String outputFile = "C:\\LEADTOOLS22\\Resources\\Images\\test.jpg"; 
		RasterImage image = LoadImage(inputFile, codecs); 
		SaveImage(image, outputFile, codecs); 
		 
		// Dispose of resources 
		codecs.dispose(); 
		image.dispose(); 
	}  
	catch(Exception ex) { 
		System.err.println(ex.getMessage()); 
		ex.printStackTrace(); 
	} 
} 

Add the below code to load an image from file.

C#
RasterImage LoadImage(String inputFile, RasterCodecs codecs) throws IOException 
{ 
	// If wanting to load from stream 
	//InputStream srcStream = Files.newInputStream(Paths.get(inputFile)); 
	//LeadStream inputStream = new LeadStream(srcStream, true); 
	//RasterImage _image = codecs.load(inputStream); 
 
	RasterImage _image = codecs.load(inputFile); 
	System.out.println("Image loaded successfully."); 
	return _image; 
} 

Note

LEADTOOLS supports loading from memory streams. The commented out code above shows one way to load a stream into a RasterImage object.

Add the below code to save the RasterImage loaded from CMP as a new JPEG file.

Java
void SaveImage(RasterImage _image, String outputFile, RasterCodecs _codecs) throws IOException 
{ 
	// If wanting to save to stream 
	//OutputStream outStream = Files.newOutputStream(Paths.get(outputFile)); 
	//LeadStream leadOutStream = new LeadStream(outStream, true); 
	//_codecs.save(_image, leadOutStream, RasterImageFormat.JPEG, _image.getBitsPerPixel()); 
 
	_codecs.save(_image, outputFile, RasterImageFormat.JPEG, _image.getBitsPerPixel()); 
	System.out.println("Image saved successfully."); 
} 

Note

LEADTOOLS also supports saving to memory streams. The commented out code above shows how to save to a stream from a RasterImage object.

Run the Project

Run the project by selecting Run -> Run.

If the steps were followed correctly, the application loads the CMP image as a RasterImage and then exports to file as JPEG.

Wrap-up

This tutorial showed how to add the necessary references to load and save an image. Also, it covered how to use the RasterImage and RasterCodecs classes.

See Also

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.