Document pdfDocument = new Document(_dataDir + "Shrinkimage.pdf"); com.aspose.pdf.optimization.OptimizationOptions optimizationOptions = new com.aspose.pdf.optimization.OptimizationOptions(); optimizationOptions.getImageCompressionOptions().setCompressImages(true); optimizationOptions.getImageCompressionOptions().setImageQuality(50); pdfDocument.optimizeResources(optimizationOptions); pdfDocument.save(_dataDir + "Shrinkimage_out.pdf");