ios - SIGABRT on cast to UIImage -

i'm using fastttcamera wrapper avfoundation taking, processing , displaying picture. here's code (a fastttcamera delegate method) in cast (fastttcapturedimage *) (uiimage *):

- (void)cameracontroller:(fastttcamera *)cameracontroller didfinishscalingcapturedimage:(fastttcapturedimage *)capturedimage {     //use captured image's data--note fastttcapturedimage cast uiimage     nsdata *pngdata = uiimagepngrepresentation((uiimage *)capturedimage);      //save image, , add path transaction's picpath attribute     nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);     nsstring *documentspath = [paths objectatindex:0]; //get docs directory      int timestamp = [[nsdate date] timeintervalsince1970];      nsstring *timetag = [nsstring stringwithformat:@"%d",timestamp];      nsstring *filepath = [documentspath stringbyappendingstring:timetag]; //add file name     [pngdata writetofile:filepath atomically:yes]; //write file      self.thistransaction.picpath = filepath;      [self.viewfinder setimage:(uiimage *)capturedimage]; } 

however, i'm getting sigabrt @ line:

    nsdata *pngdata = uiimagepngrepresentation((uiimage *)capturedimage); 

with console readout:

 *** terminating app due uncaught exception 'nsinvalidargumentexception', reason: '-[fastttcapturedimage cgimage]: unrecognized selector sent instance 0x17e2a100' 

i'm confused reference cgimage. problem typecast? there no complaint on build. can please set me straight?

read docs fastttcapturedimage. it's not uiimage can't cast that. use provided property uiimage.

change problematic line to:

nsdata *pngdata = uiimagepngrepresentation(capturedimage.fullimage); 

you have same problem later:

[self.viewfinder setimage:capturedimage.fullimage]; 

btw - didn't problem while compiling because cast way tell compiler "trust me, it's i'm telling is". problem here wrong, it's not claimed was. :)