/// <summary>
/// Creates and initializes a new lens tilt depth-of-field effect.
/// </summary>
/// <param name="source">The source image to be blurred.</param>
/// <param name="focusBand">The band that represents the focus area in the image. Pixels within this band won't be blurred.
/// Areas outside of the area will be progressively more blurred as the distance from the focus band increases..</param>
/// <param name="blurStrengthAtEdge1">Strength of the blur on the Edge1 side of the focus band.</param>
/// <param name="blurStrengthAtEdge2">Strength of the blur on the Edge2 side of the focus band.</param>
public LensTiltDepthOfFieldEffect(IImageProvider source, FocusBand focusBand, double strengthAtEdge1, double strengthAtEdge2, DepthOfFieldQuality quality)
: base(source, quality)
{
FocusBand = focusBand;
StrengthAtEdge1 = strengthAtEdge1;
StrengthAtEdge2 = strengthAtEdge2;
}
/// <summary>
/// Creates and initializes a new lens tilt depth-of-field effect.
/// </summary>
/// <param name="source">The source image to be blurred.</param>
/// <param name="focusBand">The band that represents the focus area in the image. Pixels within this band won't be blurred.
/// Areas outside of the area will be progressively more blurred as the distance from the focus band increases..</param>
/// <param name="blurStrengthAtEdge1">Strength of the blur on the Edge1 side of the focus band.</param>
/// <param name="blurStrengthAtEdge2">Strength of the blur on the Edge2 side of the focus band.</param>
public LensTiltDepthOfFieldEffect(IImageProvider source, FocusBand focusBand, double strengthAtEdge1, double strengthAtEdge2, DepthOfFieldQuality quality)
: base(source, quality)
{
FocusBand = focusBand;
StrengthAtEdge1 = strengthAtEdge1;
StrengthAtEdge2 = strengthAtEdge2;
}
private FocusBand GetBandFromHorizonLine(Point p1, Point p2)
{
double xDiff = p1.X - p2.X;
double yDiff = p1.Y - p2.Y;
Point midpoint = new Point((p2.X + p1.X) / 2, (p2.Y + p1.Y) / 2);
Func <double, Point> lineNormalFunction;
if (Math.Abs(xDiff) < 1e-3)
{
//special case to avoid divide by zero
lineNormalFunction = (x) => new Point(midpoint.X + x, midpoint.Y);
}
else if (Math.Abs(yDiff) < 1e-3)
{
//special case to avoid divide by zero
lineNormalFunction = (y) => new Point(midpoint.X, midpoint.Y + y);
}
else
{
double slope = (p2.Y - p1.Y) / (p2.X - p1.X);
double perpSlope = -1 / slope;
double intercept = midpoint.Y - (perpSlope * midpoint.X);
lineNormalFunction = (x) => new Point(midpoint.X + x, (perpSlope * (midpoint.X + x)) + intercept);
}
FocusBand band = new FocusBand(lineNormalFunction(0), lineNormalFunction(1e-5));
return(band);
}
protected override MaybeTask<IImageProvider> GetEffectInternalAsync(IImageProvider source, Windows.Foundation.Size sourceSize, Windows.Foundation.Size renderSize)
{
if (m_effectEffect == null)
{
m_focus = new FocusBand(new Point(0.5, 0.3), new Point(0.5, 0.4));
m_effectEffect = new LensTiltDepthOfFieldEffect(source, m_focus, 1.0, 1.0, DepthOfFieldQuality.Preview);
}
else if (m_effectEffect.Source != source)
{
m_effectEffect.Source = source;
}
return new MaybeTask<IImageProvider>(m_effectEffect);
}
private static async Task RenderEffect(FocusBand focusBand, DepthOfFieldQuality quality, [CallerMemberName] string testName = "")
{
using (var source = KnownImages.Nurse.ImageSource)
using (var effect = new LensTiltDepthOfFieldEffect(source, focusBand, 1.0, 1.0, quality))
using (var renderer = new JpegRenderer(effect))
{
var buffer = await renderer.RenderAsync();
ImageResults.Instance.SaveToPicturesLibrary(buffer, "LensTiltDepthOfFieldEffectTest_" + testName + ".jpg");
}
}
public async Task RenderWithZeroWidthFocusAreaSuccedes()
{
var verticalZeroBand = new FocusBand(new Point(0.3, 0.5), new Point(0.3, 0.5));
await RenderEffect(verticalZeroBand, DepthOfFieldQuality.Full);
var horizontalZeroBand = new FocusBand(new Point(0.5, 0.7), new Point(0.5, 0.7));
await RenderEffect(horizontalZeroBand, DepthOfFieldQuality.Full);
}
public async Task RenderWithFullFocusAreaSuccedes()
{
var verticalFullBand = new FocusBand(new Point(0.0, 0.5), new Point(1.0, 0.5));
await RenderEffect(verticalFullBand, DepthOfFieldQuality.Full);
var horizontalFullBand = new FocusBand(new Point(0.5, 0.0), new Point(0.5, 1.0));
await RenderEffect(horizontalFullBand, DepthOfFieldQuality.Full);
}
private FocusBand GetBandFromHorizonLine(Point p1, Point p2)
{
double xDiff = p1.X - p2.X;
double yDiff = p1.Y - p2.Y;
Point midpoint = new Point((p2.X + p1.X) / 2, (p2.Y + p1.Y) / 2);
Func<double, Point> lineNormalFunction;
if (Math.Abs(xDiff) < 1e-3)
{
//special case to avoid divide by zero
lineNormalFunction = (x) => new Point(midpoint.X + x, midpoint.Y);
}
else if (Math.Abs(yDiff) < 1e-3)
{
//special case to avoid divide by zero
lineNormalFunction = (y) => new Point(midpoint.X, midpoint.Y + y);
}
else
{
double slope = (p2.Y - p1.Y) / (p2.X - p1.X);
double perpSlope = -1 / slope;
double intercept = midpoint.Y - (perpSlope * midpoint.X);
lineNormalFunction = (x) => new Point(midpoint.X + x, (perpSlope * (midpoint.X + x)) + intercept);
}
FocusBand band = new FocusBand(lineNormalFunction(0), lineNormalFunction(1e-5));
return band;
}
