Compress PDF Documents | Reduce PDF Size and Optimize PDF in Java

Compress-PDF-RGB-Grayscale.java

// Open document
Document pdfDocument = new Document("Compress.pdf");

// Convert RGB to Grayscale PDF
com.aspose.pdf.RgbToDeviceGrayConversionStrategy strategy = new com.aspose.pdf.RgbToDeviceGrayConversionStrategy();
for (int idxPage = 1; idxPage <= pdfDocument.getPages().size(); idxPage++) {
    com.aspose.pdf.Page page = pdfDocument.getPages().get_Item(idxPage);
    strategy.convert(page);
}

// Save the grayscale PDF file
pdfDocument.save("Compressed.pdf");

Compress-PDF-Shrink-Images.java

// Open document
Document pdfDocument = new Document("Compress.pdf");

// Initialize OptimizationOptions
com.aspose.pdf.optimization.OptimizationOptions optimizationOptions = new com.aspose.pdf.optimization.OptimizationOptions();

// Set CompressImages option
optimizationOptions.getImageCompressionOptions().setCompressImages(true);

// Set ImageQuality option
optimizationOptions.getImageCompressionOptions().setImageQuality(50);

// Compress PDF document using OptimizationOptions
pdfDocument.optimizeResources(optimizationOptions);

// Save updated compressed PDF document
pdfDocument.save("Compressed.pdf");

Compress-PDF.java

// Open document
Document pdfDocument = new Document("Compress.pdf");

// Compress PDF document by optimizing resources
pdfDocument.optimizeResources();

// Save output document
pdfDocument.save("Compressed.pdf");