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.

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>\LEADTOOLS23\Bin\Java

• leadtools.jar
• leadtools.codecs.jar

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:

• Evaluation license, obtained at the time the evaluation toolkit is downloaded. It allows the toolkit to be evaluated.
• Deployment license. If a Deployment license file and developer key are needed, refer to Obtaining a License.

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.

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

import java.io.*; 
import java.nio.file.Files; 
import java.nio.file.Paths; 
 
import leadtools.*; 
import leadtools.codecs.*; 

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.

public static void main(String[] args) throws IOException 
{ 
	new _Main().run(args); 
} 
private void run(String[] args) { 
	try { 
		Platform.setLibPath("C:\\LEADTOOLS23\\Bin\\CDLL\\x64"); 
		Platform.loadLibrary(LTLibrary.LEADTOOLS); 
		Platform.loadLibrary(LTLibrary.CODECS); 
			 
		SetLicense(); 
			 
		RasterCodecs codecs = new RasterCodecs(); 
		String inputFile = "C:\\LEADTOOLS23\\Resources\\Images\\image1.cmp"; 
		String outputFile = "C:\\LEADTOOLS23\\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.

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.

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

• LEADTOOLS RasterImage Documentation
• LEADTOOLS RasterCodecs Documentation
• LEADTOOLS SDK Download