/// <summary>
/// Checks whether or not this defined term is the same as <paramref name="other"/>.
/// </summary>
public bool Equals(Units other)
{
return Code == other.Code;
}
/// <summary>
/// Checks if operations in the given <paramref name="units"/> are possible with the <paramref name="pixelSpacing"/> information available.
/// </summary>
/// <returns>True if such operations are valid; False if no such operation is possible.</returns>
protected static bool ValidateUnits(Units units, PixelSpacing pixelSpacing)
{
return (units == Units.Pixels || !pixelSpacing.IsNull);
}
/// <summary>
/// Converts an area in pixels into the given units given some particular pixel spacing.
/// </summary>
/// <param name="area">The area of pixels to be converted.</param>
/// <param name="units">The units into which the area should be converted.</param>
/// <param name="pixelSpacing">The pixel spacing information available.</param>
/// <returns>The equivalent area in the units of <paramref name="units"/>.</returns>
/// <exception cref="ArgumentException">Thrown if <paramref name="units"/> is a physical unit of measurement and <paramref name="pixelSpacing"/> is not calibrated.</exception>
protected static double ConvertFromSquarePixels(double area, Units units, PixelSpacing pixelSpacing)
{
if (!ValidateUnits(units, pixelSpacing))
throw new ArgumentException("Pixel spacing must be calibrated in order to compute physical units.", "units");
double factor = 1;
switch (units)
{
case Units.Pixels:
factor = 1;
break;
case Units.Centimeters:
factor = pixelSpacing.Column*pixelSpacing.Row/100;
break;
case Units.Millimeters:
default:
factor = pixelSpacing.Column*pixelSpacing.Row;
break;
}
return area*factor;
}
/// <summary>
/// Helper method to compute the physical distance between two pixels.
/// </summary>
/// <param name="point1">The first point.</param>
/// <param name="point2">The second point.</param>
/// <param name="normalizedPixelSpacing">The normalized pixel spacing of the image.</param>
/// <param name="units">The units in which the resultant distance is given, passed by reference. If <paramref name="normalizedPixelSpacing"/> is not calibrated, then the passed variable will change to <see cref="RoiGraphics.Units.Pixels"/>.</param>
/// <returns>The distance between the two points, in units of <paramref name="units"/>.</returns>
public static double CalculateLength(
PointF point1,
PointF point2,
PixelSpacing normalizedPixelSpacing,
ref Units units)
{
if (normalizedPixelSpacing.IsNull)
units = Units.Pixels;
double widthInPixels = point2.X - point1.X;
double heightInPixels = point2.Y - point1.Y;
double length;
if (units == Units.Pixels)
{
length = Math.Sqrt(widthInPixels*widthInPixels + heightInPixels*heightInPixels);
}
else
{
double widthInMm = widthInPixels*normalizedPixelSpacing.Column;
double heightInMm = heightInPixels*normalizedPixelSpacing.Row;
double lengthInMm = Math.Sqrt(widthInMm*widthInMm + heightInMm*heightInMm);
if (units == Units.Millimeters)
length = lengthInMm;
else
length = lengthInMm/10;
}
return length;
}
