Mostly It's a 3 Step Process :
1) Get the photo. Store it to the Documents Directory. Apple has described it very well here : PhotoPicker
2) Fetch the Photo from Document Directory :
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:@"Images"];
UIImage *image = [[UIImage alloc] initWithContentsOfFile:[dataPath stringByAppendingPathComponent:[NSString stringWithFormat:@"yourImage.png"]]];
3) Now , you can upload your Photo to the Server. The Process is well described Here :
upload image from iphone to the server folder