CIContext *context = [CIContext contextWithOptions:nil];   
    CIImage *inputImage = [[CIImage alloc] initWithImage:[UIImage imageNamed:@"1.png"]];   
    // create gaussian blur filter   
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];   
    [filter setValue:inputImage forKey:kCIInputImageKey];   
    [filter setValue:[NSNumber numberWithFloat:10.0] forKey:@"inputRadius"];   
    // blur image   
    CIImage *result = [filter valueForKey:kCIOutputImageKey];   
    CGImageRef cgImage = [context createCGImage:result fromRect:[result extent]];   
    UIImage *image = [UIImage imageWithCGImage:cgImage];   
    CGImageRelease(cgImage);   
    self.mainImageView.image = image;