iphone - Writing orignal image with exif to Document Directory folder from ALAsset object -

i want save alasset imagearray directly document directory exif tried png conversion, jpeg conversion nothing worked creating new image either jpg or png (loss of exif)

i have seen time save nsdata directly folder preserve exif dont know how

i getting metadata alasset object result

nsdictionary *metadata = [[result defaultrepresentation] metadata]; 

another assets array list of images

alassetsgroupenumerationresultsblock assetenumerator = ^(alasset *result, nsuinteger index, bool *stop) {         if(result != null) {             [assets addobject:result];              ;           nslog(@"assets %i",[assets count]);             self.progressview.progress = (float)index / ([assets count]-1);         } 

saving images document directory folder

-(void)saveimagestodocumentdirectory{     nslog(@"assets count %i",[assets count]);      for(int i=0;i<[assets count];i++)     {         currentimage = [uiimage imagewithcgimage:[[[assets objectatindex:i] defaultrepresentation] fullresolutionimage]];          [self saveimage:currentimage withimagename:[nsstring stringwithformat:@"images %d",i]];          }   }      - (void)saveimage:(uiimage*)image withimagename:(nsstring*)imagename {         nsdata *imagedata = uiimagepngrepresentation(image); //convert image .png format.       // nsdata *imagedata = uiimagejpegrepresentation(image,1.0);         nsfilemanager *filemanager = [nsfilemanager defaultmanager];//create instance of nsfilemanager         nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes); //create array , store result of our search documents directory in         nsstring *documentsdirectory = [paths objectatindex:0]; //create nsstring object, holds our exact path documents directory         nsstring *datapath = [documentsdirectory stringbyappendingpathcomponent:@"myfolder"];         nsstring *fullpath = [datapath stringbyappendingpathcomponent:[nsstring stringwithformat:@"%@.png", imagename]]; //add our image path         [filemanager createfileatpath:fullpath contents:imagedata attributes:nil]; //finally save path (image)          nslog(@"image saved"); } 

this method able write images in document directory folder exif remain intact, hope other users

-(void)writingoutimage{     nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);     nsstring *documentsdirectory = [paths objectatindex:0]; // documents folder     nsstring *documentdatapath = [documentsdirectory stringbyappendingpathcomponent:@"myfolder"];     nslog(@"documentdatapath %@",documentdatapath);     (int j=0; j<[assets count]; j++) {          alassetrepresentation *representation = [[assets objectatindex:j] defaultrepresentation];         nsstring* filename = [documentdatapath stringbyappendingpathcomponent:[representation filename]];          [[nsfilemanager defaultmanager] createfileatpath:filename contents:nil attributes:nil];         nsoutputstream *outputstream = [nsoutputstream outputstreamtofileatpath:filename append:yes];         [outputstream open];          long long offset = 0;         long long bytesread = 0;          nserror *error;         uint8_t * buffer = malloc(131072);         while (offset<[representation size] && [outputstream hasspaceavailable]) {             bytesread = [representation getbytes:buffer fromoffset:offset length:131072 error:&error];             [outputstream write:buffer maxlength:bytesread];             offset = offset+bytesread;         }         [outputstream close];         free(buffer);     } }