我如何從CIImage獲取CGBItmapContextCreate

我有以下使用UISlider時應用的過濾器。我如何從CIImage獲取CGBItmapContextCreate

- (IBAction)exposureSliderChanged:(id)sender { 

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 

    exposureFilter = [CIFilter filterWithName: @"CIExposureAdjust" keysAndValues: @"inputImage", aCIImage, nil]; 
    [exposureFilter setValue:[NSNumber numberWithFloat:_slider.value] forKey:@"inputEV"]; 
    exposureValue=_slider.value; 

    dispatch_async(dispatch_get_main_queue(), ^{ 
     outputImage = [exposureFilter outputImage]; 
     CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]]; 
     _modifiedImage = [UIImage imageWithCGImage:cgimg scale:2.0 orientation:UIImageOrientationUp]; 
     [_cropImageView setImage:_modifiedImage]; 
     CGImageRelease(cgimg); 
    }); 

; 


}); 

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
    exposureDict = [NSDictionary dictionaryWithObjectsAndKeys: 
        [NSNumber numberWithFloat:(float)_slider.value],@"Exposure", nil]; 
});

}

我希望能夠得到以應用懷舊濾鏡產生的圖像的原始數據。棕褐色過濾器的代碼：

- (IBAction)sepiaFilterButtonPressed:(id)sender { 

_slider.hidden=YES; 

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 

    _undoImage=[_modifiedImage copy]; 

    SepiaToneEffect *sepiaToneEffect = [[SepiaToneEffect alloc] init]; 
    [sepiaToneEffect setImageWidth: imageWidth]; 
    [sepiaToneEffect setImageHeight: imageHeight]; 

    //set the blurred image to your imageView in the main thread 
    dispatch_async(dispatch_get_main_queue(), ^{ 
     NSLog(@"%f",_modifiedImage.size.width); 

     _modifiedImage = [sepiaToneEffect modifyImageWithSepia:_modifiedImage 
                imageRawData:imageRawData 
                withColorR:112 
                 colorG:66 
                 colorB:20 
                 depth:0.5]; 
     _modifiedImage=[Globals imageWithImage:_modifiedImage scaledToSize:sizeNeeded]; 

     NSLog(@"%f",_modifiedImage.size.width); 
     [_cropImageView setImage:_modifiedImage]; 
     //Create CIImage 
     UIImage *aUIImage =_modifiedImage; 
     CGImageRef aCGImage = aUIImage.CGImage; 
     aCIImage = [CIImage imageWithCGImage:aCGImage]; 

     //Create context 
     context = [CIContext contextWithOptions:nil]; 

    }); 

    NSDictionary *modification = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithBool:YES], @"Sepia",nil]; 
    [[kAppDelegate modificationsArray] addObject:modification]; 

});

}

是否有過過濾器應用過濾器的方法？例如： 1-應用曝光濾鏡; 2-應用曝光後產生的圖像上的棕褐色。

來源

2014-10-28 Stefan Olaru

我設法應用過濾器（CIFilter）在過濾器上寫滑塊的方法，這個代碼（在使用CGContextCreate位圖）（exposureSliderChanged：（ID）發送）：

imageRawData = realloc(imageRawData,CGImageGetHeight(_modifiedImage.CGImage)*CGImageGetWidth(_modifiedImage.CGImage)*4); 

     localData = CGBitmapContextCreate(imageRawData, 
              imageWidth, 
              imageHeight, 
              bitsPerComponent, 
              bytesPerRow, 
              colorSpace, 
              kCGImageAlphaPremultipliedLast | kCGBitmapByteOrderDefault); 


     CGContextDrawImage(localData, CGRectMake(0, 0, imageWidth, imageHeight),cgimg); 
     CGContextRelease(localData); 
     CFRelease(localData);

來源

2014-10-28 15:29:14

我如何從CIImage獲取CGBItmapContextCreate

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