public static UIImage CreateBlurImageFromView(UIView view)
{
var blurRadius = 2f;
var _size = view.Bounds.Size;
UIGraphics.BeginImageContext(_size);
view.DrawViewHierarchy(view.Bounds, false);
var viewImage = UIGraphics.GetImageFromCurrentImageContext();
// Blur Image
var gaussianBlurFilter = new CIGaussianBlur();
gaussianBlurFilter.Image = CIImage.FromCGImage(viewImage.CGImage);
gaussianBlurFilter.Radius = blurRadius;
var resultImage = gaussianBlurFilter.OutputImage;
var croppedImage = resultImage.ImageByCroppingToRect(new CGRect(blurRadius, blurRadius, _size.Width - 2 * blurRadius, _size.Height - 2 * blurRadius));
var transformFilter = new CIAffineTransform();
var affineTransform = CGAffineTransform.MakeTranslation(-blurRadius, blurRadius);
transformFilter.Transform = affineTransform;
transformFilter.Image = croppedImage;
var transformedImage = transformFilter.OutputImage;
return(new UIImage(transformedImage));
}
public static void Colourize(NSView control, Color color, Action drawAction)
{
var size = control.Frame.Size;
if (size.Width <= 0 || size.Height <= 0)
{
return;
}
var image = new NSImage(size);
image.LockFocusFlipped(control.IsFlipped);
drawAction();
image.UnlockFocus();
var ciImage = CIImage.FromCGImage(image.CGImage);
SD.SizeF realSize;
if (control.RespondsToSelector(selConvertSizeToBacking))
{
realSize = control.ConvertSizeToBacking(size);
}
else
{
realSize = control.ConvertSizeToBase(size);
}
if (control.IsFlipped)
{
var affineTransform = new NSAffineTransform();
affineTransform.Translate(0, realSize.Height);
affineTransform.Scale(1, -1);
var filter1 = new CIAffineTransform();
filter1.Image = ciImage;
filter1.SetValueForKey(affineTransform, CIInputTransform);
ciImage = filter1.ValueForKey(CIOutputImage) as CIImage;
}
var filter2 = new CIColorControls();
filter2.SetDefaults();
filter2.Image = ciImage;
filter2.Saturation = 0.0f;
ciImage = filter2.ValueForKey(CIOutputImage) as CIImage;
var filter3 = new CIColorMatrix();
filter3.SetDefaults();
filter3.Image = ciImage;
filter3.RVector = new CIVector(0, color.R, 0);
filter3.GVector = new CIVector(color.G, 0, 0);
filter3.BVector = new CIVector(0, 0, color.B);
ciImage = filter3.ValueForKey(CIOutputImage) as CIImage;
ciImage.Draw(new SD.RectangleF(SD.PointF.Empty, size), new SD.RectangleF(SD.PointF.Empty, realSize), NSCompositingOperation.SourceOver, 1);
}
public CIImage AffineTransform()
{
// Create an AffineTransform to Skew the Image
var transform = new CGAffineTransform(1F, .5F, .5F, 1F, 0F, 0F);
var affineTransform = new CIAffineTransform()
{
Image = flower,
Transform = transform
};
return(affineTransform.OutputImage);
}
public CVPixelBuffer CroppedSampleBuffer(CMSampleBuffer sampleBuffer)
{
var imageBuffer = sampleBuffer.GetImageBuffer();
if (imageBuffer == null)
{
throw new ArgumentException("Cannot convert to CVImageBuffer");
}
// Only doing these calculations once for efficiency.
// If the incoming images could change orientation or size during a session, this would need to be reset when that happens.
if (!alreadySet)
{
alreadySet = true;
var imageSize = imageBuffer.EncodedSize;
/*
* Incoming image size is set in VideoCapture.BeginSession as AVCaptureSession.Preset1920x1080;
* Which, buffer-wise, is always captured landscape-style, but info.plist specifies that this
* app runs only in portrait. Therefore, the buffer is always sideways, i.e., `imageSize == [Width: 1920, Height: 1080]`
*
* Since our UI blurs out the top and bottom of the image, what we're interested in is the middle
* 3/5 of the long side, and the entirety of the 1080 (short side), rotated 90 degrees anti-clockwise.
*
* To get good alignment, this also requires some manual tweaking (LayoutMargins?), which probably changes
* between hardware
*/
var rotatedSize = new CGSize(imageSize.Height, imageSize.Width);
var shorterSide = rotatedSize.Width < rotatedSize.Height ? rotatedSize.Width : rotatedSize.Height;
rotateTransform = new CIAffineTransform
{
Transform = new CGAffineTransform(0, -1, 1, 0, 0, shorterSide)
};
cropTransform = new CIAffineTransform
{
Transform = CGAffineTransform.MakeTranslation(0, (int)(1920.0 / 5) + 60) // Translate down past the cropped area + manual tweak
};
edgeDetector = new CIEdges();
}
// Convert to CIImage because it is easier to manipulate
var ciImage = CIImage.FromImageBuffer(imageBuffer);
rotateTransform.Image = ciImage;
cropTransform.Image = rotateTransform.OutputImage;
edgeDetector.Image = cropTransform.OutputImage;
var cropped = edgeDetector.OutputImage;
// Note that the above pipeline could be easily appended with other image manipulations.
// For example, to change the image contrast, detect edges, etc. It would be most efficient to handle all of
// the image manipulation in a single Core Image pipeline because it can be hardware optimized.
// Only need to create this buffer one time and then we can reuse it for every frame
if (resultBuffer == null || resultBuffer.Handle == IntPtr.Zero)
{
var targetSize = new CGSize(1080, 1152); //1080, 3/5 * 1920
byte[] data = new byte[(int)targetSize.Height * 4 * (int)targetSize.Width];
resultBuffer = CVPixelBuffer.Create((nint)targetSize.Width, (nint)targetSize.Height, CVPixelFormatType.CV32BGRA, data, 4 * (nint)targetSize.Width, null);
if (resultBuffer == null)
{
throw new Exception("Can't allocate pixel buffer.");
}
}
context.Render(cropped, resultBuffer);
// For debugging
//var image = ImageBufferToUIImage(resultBuffer);
//Console.WriteLine("Image size: " + image.Size); // set breakpoint to see image being provided to CoreML
return(resultBuffer);
}
public CVPixelBuffer CroppedSampleBuffer(CMSampleBuffer sampleBuffer, CGSize targetSize)
{
var imageBuffer = sampleBuffer.GetImageBuffer();
if (imageBuffer == null)
{
throw new ArgumentException("Cannot convert to CVImageBuffer");
}
// Only doing these calculations once for efficiency.
// If the incoming images could change orientation or size during a session, this would need to be reset when that happens.
if (!alreadySet)
{
alreadySet = true;
var imageSize = imageBuffer.EncodedSize;
var rotatedSize = new CGSize(imageSize.Height, imageSize.Width);
if (targetSize.Width > rotatedSize.Width || targetSize.Height > rotatedSize.Height)
{
throw new NotSupportedException("Captured image is smaller than image size for model.");
}
var shorterSide = rotatedSize.Width < rotatedSize.Height ? rotatedSize.Width : rotatedSize.Height;
rotateTransform = new CIAffineTransform
{
Transform = new CGAffineTransform(0, -1, 1, 0, 0, shorterSide)
//Transform = CGAffineTransform.MakeIdentity()
};
var scale = targetSize.Width / shorterSide;
scaleTransform = new CIAffineTransform
{
Transform = CGAffineTransform.MakeScale(scale, scale),
};
var xDiff = rotatedSize.Width * scale - targetSize.Width;
var yDiff = rotatedSize.Height * scale - targetSize.Height;
cropTransform = new CIAffineTransform
{
//Transform = CGAffineTransform.MakeTranslation(xDiff / 2.0f, yDiff / 2.0f),
Transform = CGAffineTransform.MakeIdentity()
};
}
// Convert to CIImage because it is easier to manipulate
var ciImage = CIImage.FromImageBuffer(imageBuffer);
rotateTransform.Image = ciImage;
scaleTransform.Image = rotateTransform.OutputImage;
cropTransform.Image = scaleTransform.OutputImage;
var cropped = cropTransform.OutputImage;
// Note that the above pipeline could be easily appended with other image manipulations.
// For example, to change the image contrast. It would be most efficient to handle all of
// the image manipulation in a single Core Image pipeline because it can be hardware optimized.
// Only need to create this buffer one time and then we can reuse it for every frame
if (resultBuffer == null || resultBuffer.Handle == IntPtr.Zero)
{
byte[] data = new byte[(int)targetSize.Height * 4 * (int)targetSize.Width];
resultBuffer = CVPixelBuffer.Create((nint)targetSize.Width, (nint)targetSize.Height, CVPixelFormatType.CV32BGRA, data, 4 * (nint)targetSize.Width, null); // HACK
if (resultBuffer == null)
{
throw new Exception("Can't allocate pixel buffer.");
}
}
context.Render(cropped, resultBuffer);
// For debugging
//var image = ImageBufferToUIImage(resultBuffer);
//Console.WriteLine("Image size: " + image.Size); // set breakpoint to see image being provided to CoreML
return(resultBuffer);
}
public CIImage AffineTransform ()
{
// Create an AffineTransform to Skew the Image
var transform = new CGAffineTransform (1F, .5F, .5F, 1F, 0F, 0F);
var affineTransform = new CIAffineTransform ()
{
Image = flower,
Transform = transform
};
return affineTransform.OutputImage;
}
