图片上添加水印图片之后合成

-(void) FeSlideFilterView:(FeSlideFilterView *)sender didTapDoneButtonAtIndex:(NSInteger)index
{
    [self dismissViewControllerAnimated:YES completion:^{
        [[UIApplication sharedApplication] setStatusBarHidden:NO];
       
        UIGraphicsBeginImageContext(self.filterImage.size);
        [self.filterImage drawInRect:CGRectMake(0, 0, self.filterImage.size.width, self.filterImage.size.height)];

//四个参数为水印图片的位置

[signImage.image drawInRect:CGRectMake(self.currentPoint.x, self.currentPoint.y, signImage.image.size.width, signImage.image.size.height)];
        UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

[deletate imageBeautifulDone:resultingImage];
    }];
    NSLog(@"did tap at index = %ld",(long)index);

}