Resizing UIImage to post to Twitter Sheet- iOS -

i trying resize image in order attach twitter sheet. getting error "no known class selector method "imagewithimage: (uiimage)image....""

- (void)twitterbuttonpressed {      uiimage *iconimage=[uiimage imagenamed:@"male_small_0.png"];     // having problem in following line     uiimage *iconimage2=[uiimage imagewithimage:iconimage scaledtosize:cgsizemake(73.0, 73.0)];  }  -(uiimage*)imagewithimage:(uiimage*)image scaledtosize:(cgsize)newsize {     uigraphicsbeginimagecontextwithoptions(newsize, no, 0.0);     [image drawinrect:cgrectmake(0, 0, newsize.width, newsize.height)];     uiimage *newimage =uigraphicsgetimagefromcurrentimagecontext();     uigraphicsendimagecontext();     return newimage;  } 

you call imagewithimage:scaledtosize: on uiimage, method implemented in assume view controller. make work, change twitterbuttonpressed to:

- (void)twitterbuttonpressed {      uiimage *iconimage=[uiimage imagenamed:@"male_small_0.png"];     // having problem in following line     uiimage *iconimage2=[self imagewithimage:iconimage scaledtosize:cgsizemake(73.0, 73.0)]; } 

a better solution create category on uiimage imagewithimage:scaledtosize: in it. then, when import category, don't need method in view controller anymore , can leave twitterbuttonpressed as-is , it'll work.