< iOS samples

OptimizerTest - Swift

The sample shows how to use 'pdftron.PDF.Optimizer' to reduce PDF file size by reducing the file size, removing redundant information, and compressing data streams using the latest in image compression technology. 'pdftron.PDF.Optimizer' is an optional Add-On to PDFNet Core SDK.

//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2017 by PDFTron Systems Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

import PDFNet
import Foundation

//---------------------------------------------------------------------------------------
// The following sample illustrates how to reduce PDF file size using 'pdftron.PDF.Optimizer'.
// The sample also shows how to simplify and optimize PDF documents for viewing on mobile devices
// and on the Web using 'pdftron.PDF.Flattener'.
//
// @note Both 'Optimizer' and 'Flattener' are separately licensable add-on options to the core PDFNet license.
//
// ----
//
// 'pdftron.PDF.Optimizer' can be used to optimize PDF documents by reducing the file size, removing
// redundant information, and compressing data streams using the latest in image compression technology.
//
// PDF Optimizer can compress and shrink PDF file size with the following operations:
// - Remove duplicated fonts, images, ICC profiles, and any other data stream.
// - Optionally convert high-quality or print-ready PDF files to small, efficient and web-ready PDF.
// - Optionally down-sample large images to a given resolution.
// - Optionally compress or recompress PDF images using JBIG2 and JPEG2000 compression formats.
// - Compress uncompressed streams and remove unused PDF objects.
// ----
//
// 'pdftron.PDF.Flattener' can be used to speed-up PDF rendering on mobile devices and on the Web by
// simplifying page content (e.g. flattening complex graphics into images) while maintaining vector text
// whenever possible.
//
// Flattener can also be used to simplify process of writing custom converters from PDF to other formats.
// In this case, Flattener can be used as first step in the conversion pipeline to reduce any PDF to a
// very simple representation (e.g. vector text on top of a background image).
//---------------------------------------------------------------------------------------

func runOptimizerTest() -> Int {
    return autoreleasepool {
        var ret: Int = 0

        // The first step in every application using PDFNet is to initialize the
        // library and set the path to common PDF resources. The library is usually
        // initialized only once, but calling Initialize() multiple times is also fine.
        
        
        //--------------------------------------------------------------------------------
        // Example 1) Simple optimization of a pdf with default settings.
        //
        do {
            try PTPDFNet.catchException {
                let doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                doc.initSecurityHandler()
                
                PTOptimizer.optimize(doc, settings: PTOptimizerSettings())
                
                doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_opt1.pdf").path, flags: e_ptlinearized.rawValue)
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        //--------------------------------------------------------------------------------
        // Example 2) Reduce image quality and use jpeg compression for
        // non monochrome images.
        do {
            try PTPDFNet.catchException {
                let doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                doc.initSecurityHandler()
                
                let image_settings: PTImageSettings = PTImageSettings()
                
                // low quality jpeg compression
                image_settings.setCompressionMode(e_ptjpeg)
                image_settings.setQuality(1)
                
                // Set the output dpi to be standard screen resolution
                image_settings.setImageDPI(144, resampling: 96)
                
                // this option will recompress images not compressed with
                // jpeg compression and use the result if the new image
                // is smaller.
                image_settings.forceRecompression(true)
                
                // this option is not commonly used since it can
                // potentially lead to larger files.  It should be enabled
                // only if the output compression specified should be applied
                // to every image of a given type regardless of the output image size
                //image_settings.ForceChanges(true);
                
                let opt_settings: PTOptimizerSettings = PTOptimizerSettings()
                opt_settings.setColorImageSettings(image_settings)
                opt_settings.setGrayscaleImageSettings(image_settings)
                
                // use the same settings for both color and grayscale images
                PTOptimizer.optimize(doc, settings: opt_settings)
                
                doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_opt2.pdf").path, flags: e_ptlinearized.rawValue)
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        //--------------------------------------------------------------------------------
        // Example 3) Use monochrome image settings and default settings
        // for color and grayscale images.
        do {
            try PTPDFNet.catchException {
                let doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "newsletter", ofType: "pdf"))
                doc.initSecurityHandler()
                
                let mono_image_settings: PTMonoImageSettings = PTMonoImageSettings()
                
                mono_image_settings.setCompressionMode(e_ptmn_jbig2)
                mono_image_settings.forceRecompression(true)
                
                let opt_settings: PTOptimizerSettings = PTOptimizerSettings()
                opt_settings.setMonoImageSettings(mono_image_settings)
                
                PTOptimizer.optimize(doc, settings: opt_settings)
                
                doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("newsletter_opt3.pdf").path, flags: e_ptlinearized.rawValue)
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        // ----------------------------------------------------------------------
        // Example 4) Use Flattener to simplify content in this document
        // using default settings
        do {
            try PTPDFNet.catchException {
                let doc: PTPDFDoc = PTPDFDoc(filepath: Bundle.main.path(forResource: "TigerText", ofType: "pdf"))
                doc.initSecurityHandler()
                
                let fl: PTFlattener = PTFlattener()
                // The following lines can increase the resolution of background
                // images.
                //fl.setDPI(300)
                //fl.setMaximumImagePixels(5000000)
                
                // This line can be used to output Flate compressed background
                // images rather than DCTDecode compressed images which is the default
                //fl.setPreferJPG(false)
                
                // In order to adjust thresholds for when text is Flattened
                // the following function can be used.
                //fl.setThreshold(e_ptthreshold_keep_most)
                
                // We use e_ptfast option here since it is usually preferable
                // to avoid Flattening simple pages in terms of size and
                // rendering speed. If the desire is to simplify the
                // document for processing such that it contains only text and
                // a background image e_simple should be used instead.
                fl.process(doc, mode: e_ptfast)
                doc.save(toFile: URL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]).appendingPathComponent("TigerText_flatten.pdf").path, flags: e_ptlinearized.rawValue)
            }
        } catch let e as NSError {
            print("\(e)")
            ret = 1
        }
        
        print("Done")
        return ret
    }
}