How to mass convert PNG to JPG (Tutorial)

Handling a vast collection of PNG images? Converting them to JPG in bulk can be extremely beneficial, especially if you need JPGs for various purposes.

PNG (Portable Network Graphics) is a format known for its lossless compression and is widely used across various devices and platforms. Converting PNG images to JPG can significantly reduce file size, making them easier to store and share without compromising too much on quality.

In this article, I’ll guide you through the process of using Java to convert PNG files to JPG format with JDeli, ensuring your images are accessible.

Mass convert PNG to JPG using Java

1. Download the JDeli trial jar.
2. Process image if needed (scale, sharpen, lighten, watermark, etc)
3. Write out BufferedImage as JPG image file

BufferedImage bufferedImage = JDeli.read(new File("pngImageFile.png"));
// Read PNG image into Java

bufferedImage = operations.apply(BufferedImage bufferedImage);
// Process image (Optional)

JDeli.write(bufferedImage, "jpg", new File("jpgImageFile.jpg"));
// Write out BufferedImage as JPEG image file

Export PNG to JPG in one line of code

With the JDeli.convert() method you can save PNG as JPG in just one line of code.

Using File

JDeli.convert(File inFile, File outFile);

JDeli.convert(InputStream inputStream, OutputStream outputStream, "jpg");

byte[] outputData = JDeli.convert(byte[] inputData, "jpg");

JDeli.convert(File inFile, EncoderOptions outputOptions, File outfile);

How to bulk convert PNG to JPG from the command line

Mass convert PNG to JPG using command line or bash, bat, and PowerShell scripts. This method also enables JDeli to be invoked from any programming language that supports creating a child process.

java -jar jdeli.jar –convert jpg "inputFileOrDir" "outputDir"

// Read an image
BufferedImage bufferedImage = JDeli.read(dicomImageFile);

// Read an image
BufferedImage bufferedImage = JDeli.read(heicImageFile);

// Write an image
JDeli.write(bufferedImage, "heic", outputStreamOrFile);

// Read an image
BufferedImage bufferedImage = JDeli.read(jpegImageFile);

// Write an image
JDeli.write(bufferedImage, "jpeg", outputStreamOrFile);

// Read an image
BufferedImage bufferedImage = JDeli.read(jpeg2000ImageFile);

// Write an image
JDeli.write(bufferedImage, "jpx", outputStreamOrFile);

// Write an image
JDeli.write(bufferedImage, "pdf", outputStreamOrFile);

// Read an image
BufferedImage bufferedImage = JDeli.read(pngImageFile);

// Write an image
JDeli.write(bufferedImage, "png", outputStreamOrFile);

// Read an image
BufferedImage bufferedImage = JDeli.read(tiffImageFile);

// Write an image
JDeli.write(bufferedImage, "tiff", outputStreamOrFile);

// Read an image
BufferedImage bufferedImage = JDeli.read(webpImageFile);

// Write an image
JDeli.write(bufferedImage, "webp", outputStreamOrFile);