Draw yr strings cheap and easy
CGContextRef context = CGBitmapContextCreate(…);
UIPushContext(context);
UITextLabel *textLabel = [[[UITextLabel alloc] initWithFrame:CGContextGetClipBoundingBox(context)] autorelease];
[textLabel setText:@”Hello world!”];
[textLabel setCentersHorizontally:YES];
[textLabel drawContentsInRect:[textLabel bounds]];
UIPopContext(context);