private NetpbmImage <TPixelComponent> CorrectOrder <TPixelComponent>(IList <Component> requestedOrder,
NetpbmImage <TPixelComponent> image)
{
Contract.Requires(requestedOrder.Count == image.Header.Components.Count);
Contract.Requires(ListsContainTheSameElements(requestedOrder, image.Header.Components));
if (requestedOrder.SequenceEqual(image.Header.Components))
{
// short-circuit
return(image.NewImageOfSameType(image.Header, image.NativeRows));
}
var newToOldOrder = new int[requestedOrder.Count];
var currentOrder = new List <int>(image.Header.Components.Select(c => (int)c));
for (int i = 0; i < requestedOrder.Count; ++i)
{
var index = currentOrder.IndexOf((int)requestedOrder[i]);
Debug.Assert(index != -1);
newToOldOrder[i] = index;
currentOrder[index] = -1;
}
Debug.Assert(currentOrder.All(o => o == -1));
var newRows = image.NativeRows.Select(originalRow => TransposeComponentOrder(originalRow, image.Header.Width, newToOldOrder));
var newHeader = new NetpbmHeader <TPixelComponent>(
image.Header.ImageType,
image.Header.Width,
image.Header.Height,
image.Header.BytesPerPixelComponent,
requestedOrder,
image.Header.HighestComponentValue
);
return(image.NewImageOfSameType(newHeader, newRows));
}
/// <summary>
/// Returns a new image which is the given image with the components of the given type inverted and changed to
/// another type.
/// </summary>
/// <typeparam name="TPixelComponent">The pixel component type being used.</typeparam>
/// <param name="image">The image whose component to invert.</param>
/// <param name="from">The component whose values to invert.</param>
/// <param name="to">The new component type of the component being inverted.</param>
/// <returns>A copy of <paramref name="image"/> where all components of type <paramref name="from"/> are
/// inverted and changed to type <paramref name="to"/>.</returns>
private NetpbmImage <TPixelComponent> InvertComponent <TPixelComponent>(NetpbmImage <TPixelComponent> image,
Component from, Component to)
{
Contract.Requires(image.Header.Components.Contains(from));
var componentIndices =
new HashSet <int>(Enumerable.Range(0, image.Header.Components.Count).Where(i => image.Header.Components[i] == from));
var newRows = image.NativeRows.Select(oldRow => InvertRowComponent(oldRow, image, componentIndices, from, to));
var newComponents = image.Header.Components.Select(c => c == from ? to : c);
var header = new NetpbmHeader <TPixelComponent>(
image.Header.ImageType,
image.Header.Width,
image.Header.Height,
image.Header.BytesPerPixelComponent,
newComponents,
image.Header.HighestComponentValue
);
return(image.NewImageOfSameType(header, newRows));
}
/// <summary>
/// Returns a new image which is the given image converted to a canonical form.
/// </summary>
/// <typeparam name="TPixelComponent">The pixel component type being used.</typeparam>
/// <param name="image">The image whose canonical form to return.</param>
/// <param name="grayscaleConversion">Whether to perform grayscale conversion and what kind.</param>
/// <returns>The new image, in canonical form.</returns>
public NetpbmImage <TPixelComponent> Canonicalize <TPixelComponent>(NetpbmImage <TPixelComponent> image,
GrayscaleConversion grayscaleConversion = GrayscaleConversion.None)
{
var ret = image.NewImageOfSameType(image.Header, image.NativeRows);
// perform grayscale conversion if necessary
if (grayscaleConversion == GrayscaleConversion.BlackToWhite && image.Header.Components.Contains(Component.Black))
{
ret = InvertComponent(ret, Component.Black, Component.White);
}
else if (grayscaleConversion == GrayscaleConversion.WhiteToBlack && image.Header.Components.Contains(Component.White))
{
ret = InvertComponent(ret, Component.White, Component.Black);
}
// canonicalize order
if (
ret.Header.Components.Count == 3 &&
ret.Header.Components.Contains(Component.Red) &&
ret.Header.Components.Contains(Component.Green) &&
ret.Header.Components.Contains(Component.Blue)
)
{
ret = CorrectOrderRGB(ret);
}
else if (
ret.Header.Components.Count == 4 &&
ret.Header.Components.Contains(Component.Red) &&
ret.Header.Components.Contains(Component.Green) &&
ret.Header.Components.Contains(Component.Blue) &&
ret.Header.Components.Contains(Component.Alpha)
)
{
ret = CorrectOrderRGBA(ret);
}
else if (
ret.Header.Components.Count == 2 &&
ret.Header.Components.Contains(Component.White) &&
ret.Header.Components.Contains(Component.Alpha)
)
{
ret = CorrectOrderWA(ret);
}
else if (
ret.Header.Components.Count == 2 &&
ret.Header.Components.Contains(Component.Black) &&
ret.Header.Components.Contains(Component.Alpha)
)
{
ret = CorrectOrderBA(ret);
}
else if (
ret.Header.Components.Count == 4 &&
ret.Header.Components.Contains(Component.Cyan) &&
ret.Header.Components.Contains(Component.Magenta) &&
ret.Header.Components.Contains(Component.Yellow) &&
ret.Header.Components.Contains(Component.Black)
)
{
ret = CorrectOrderCMYK(ret);
}
else if (
ret.Header.Components.Count == 5 &&
ret.Header.Components.Contains(Component.Cyan) &&
ret.Header.Components.Contains(Component.Magenta) &&
ret.Header.Components.Contains(Component.Yellow) &&
ret.Header.Components.Contains(Component.Black) &&
ret.Header.Components.Contains(Component.Alpha)
)
{
ret = CorrectOrderCMYKA(ret);
}
return(ret);
}
