//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2012 by PDFTron Systems Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

#import <OBJC/PDFNetOBJC.h>
#import <Foundation/Foundation.h>

// This sample project illustrates how to recompress bi-tonal images in an 
// existing PDF document using JBIG2 compression. The sample is not intended 
// to be a generic PDF optimization tool.
//
// You can download the entire document using the following link:
//   http://www.pdftron.com/net/samplecode/data/US061222892.pdf
//
int main(int argc, char *argv[]) 
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	[PDFNet Initialize: 0];
	
	@try 
	{
		PDFDoc *pdf_doc = [[[PDFDoc alloc] initWithFilepath: @"../../TestFiles/US061222892-a.pdf"] autorelease];
		[pdf_doc InitSecurityHandler];

		SDFDoc *cos_doc = [pdf_doc GetSDFDoc];
		int num_objs = [cos_doc XRefSize];
        int i=1;
		for(; i<num_objs; ++i) 
		{
			Obj *obj = [cos_doc GetObj: i];
			if(obj && ![obj IsFree] && [obj IsStream]) 
			{
				// Process only images
				DictIterator *itr = [obj Find: @"Subtype"];
				if(![itr HasNext] || !([[itr Value] GetName] == @"Image"))
					continue;
				
				Image *input_image = [[[Image alloc] initWithImage_xobject: obj] autorelease];
				// Process only gray-scale images
				if([input_image GetComponentNum] != 1)
					continue;
				int bpc = [input_image GetBitsPerComponent];
				if(bpc != 1)	// Recompress only 1 BPC images
					continue;

				// Skip images that are already compressed using JBIG2
				itr = [obj Find: @"Filter"];
				if ([itr HasNext] && [[itr Value] IsName] && 
					[[itr Value] GetName] == @"JBIG2Decode") continue; 

				Filter *filter=[obj GetDecodedStream];
				FilterReader *reader = [[[FilterReader alloc] initWithFilter: filter] autorelease];


				ObjSet *hint_set = [[[ObjSet alloc] init] autorelease]; 	// A hint to image encoder to use JBIG2 compression
				Obj *hint=[hint_set CreateArray];
			
				[hint PushBackName: @"JBIG2"];
				[hint PushBackName: @"Lossless"];

				Image *new_image = [Image CreateWithFilterData: cos_doc image_data: reader width: [input_image GetImageWidth] height: [input_image GetImageHeight] bpc: 1 color_space: [ColorSpace CreateDeviceGray] encoder_hints: hint];

				Obj *new_img_obj = [new_image GetSDFObj];
				itr = [obj Find: @"Decode"];
				if([itr HasNext])
					[new_img_obj Put: @"Decode" obj: [itr Value]];
				itr = [obj Find: @"ImageMask"];
				if ([itr HasNext])
					[new_img_obj Put: @"ImageMask" obj: [itr Value]];
				itr = [obj Find: @"Mask"];
				if ([itr HasNext])
					[new_img_obj Put: @"Mask" obj: [itr Value]];

				[cos_doc Swap: i obj_num2: [new_img_obj GetObjNum]];
			}
		}

		[pdf_doc SaveToFile: @"../../TestFiles/Output/US061222892_JBIG2.pdf" flags: e_remove_unused];
	}
	@catch(NSException *e)
	{
		NSLog(@"%@", [e reason]);
		NSLog(@"Please make sure that the pathname to the test file is correct.");
	}
	
	NSLog(@"Done.");
	[pool release];
	return 0;
}