title: some issue when i try to use two CIFilter
body: <p>i want to have a picture black&amp;white the most clear as possible, for an app iPad et iPhone.</p>
  
  <p>i did many thing for that :</p>
  
  <p>1 - i take my picture with iPad's or iPhone's camera.</p>
  
  <p>2 - i apply my first filter == CIColorMonochrome == and i display to be sure if that work.
  my first filter work well.</p>
  
  <p>3 - i recover the result of my last filter and i use it to apply my new filter == CINoiseReduction == and i display it to be sure if that work too ! but this time it display nothing so i don't know why.</p>
  
  <pre><code>      //CIColorMonochrome
      CIFilter * monochromeFilter;
      monochromeFilter = [CIFilter filterWithName:@"CIColorMonochrome"];
      [monochromeFilter setValue:beginImage forKey:@"inputImage"];
  
      //Red Green Blue Alpha
      [monochromeFilter setValue:[CIColor colorWithString:@"255 255 255 1.0"] forKey:@"inputColor"];
  
      [monochromeFilter setValue:[NSNumber numberWithFloat:1] forKey:@"inputIntensity"];
      CIImage* monochromeImage = [monochromeFilter valueForKey:@"outputImage"];
      CIImage* outputImage = monochromeImage;
  
      //---===---
  
      CIFilter* noiseReductionFilter = [CIFilter filterWithName:@"CINoiseReduction"];
  
      //[noiseReductionFilter setDefaults];
  
      [noiseReductionFilter setValue:outputImage forKey:@"inputImage"];
      [noiseReductionFilter setValue:[NSNumber numberWithFloat:0.2] forKey:@"inputNoiseLevel"];
      [noiseReductionFilter setValue:[NSNumber numberWithFloat:0.40] forKey:@"inputSharpness"];
      [noiseReductionFilter retain];
  
      CIImage* noiseReductionImage = [noiseReductionFilter valueForKey:@"outputImage"];
  
      // ---===---
      outputImage = noiseReductionImage;
  
      CGImageRef cgimg = [context createCGImage:outputImage fromRect:[beginImage extent]];
      UIImage* newImg = [UIImage imageWithCGImage:cgimg];
      CGImageRelease(cgimg);
  
      [imageView removeFromSuperview];
  
      CGRect imageFrame = [imageView frame];
  
      [imageView release];
  
     // [self noiseReduction:newImg];
  
      imageView = [[UIImageView alloc]initWithImage:newImg]; 
      NSLog(@"%@ ===---=== " ,[self noiseReduction:newImg]);
      if (flag == 0)
          [imageView setFrame:imageFrame]; NSLog(@"setFrame image");
  
      NSLog(@"%@ ==== ", imageView);
  
      [[self view]addSubview:imageView];
  </code></pre>
  
  <p>cordially</p>