/// <summary>
/// Load color look-up table from file.
/// </summary>
/// <param name="path">File name.</param>
/// <returns>Loaded color look-up table.</returns>
public static Color32[] LoadLUT(string path)
{
try
{
byte[] data;
using (var stream = IOManager.CreateFileReference(path).OpenRead())
{
var length = (int)stream.Length;
if (length != (256 * 3)) return null;
data = new byte[length];
stream.Read(data, 0, length);
}
var lut = new Color32[256];
for (var i = 0; i < 256; i++)
{
lut[i] = new Color32(0xff, data[i], data[i + 256], data[i + 512]);
}
return lut;
}
catch
{
return null;
}
}
/// <summary>
/// Returns the reverse of an existing color table.
/// </summary>
/// <param name="lut">Look-up table subject to reversal.</param>
/// <returns>Reversed look-up table.</returns>
public static Color32[] Reverse(Color32[] lut)
{
Color32[] clone = new Color32[lut.Length];
Array.Copy(lut, clone, clone.Length);
Array.Reverse(clone);
return clone;
}
public static void SaveLUT(string file, Color32[] lut) {
if (lut.Length != 256) return;
FileStream fs = new FileStream(file, FileMode.Create);
for (int i = 0; i < 256; i++) fs.WriteByte(lut[i].R);
for (int i = 0; i < 256; i++) fs.WriteByte(lut[i].G);
for (int i = 0; i < 256; i++) fs.WriteByte(lut[i].B);
fs.Close();
}
public static void SaveLUT(string file, Color32[] lut) {
if (lut.Length != 256) return;
using (FileStream fs = new FileStream(file, FileMode.Create))
{
fs.Write(lut.Select(color => color.R).ToArray(), 0, lut.Length);
fs.Write(lut.Select(color => color.G).ToArray(), 0, lut.Length);
fs.Write(lut.Select(color => color.B).ToArray(), 0, lut.Length);
}
}
private static Color32[] InitGrayscaleLUT(bool reverse) {
Color32[] LUT = new Color32[256];
int i;
byte b;
if (reverse) {
for (i = 0, b = 255; i < 256; i++, b--) {
LUT[i] = new Color32(0xff, b, b, b);
}
} else {
for (i = 0, b = 0; i < 256; i++, b++) {
LUT[i] = new Color32(0xff, b, b, b);
}
}
return LUT;
}
public static Color32[] LoadLUT(string file) {
try {
byte[] data = File.ReadAllBytes(file);
if (data.Length != (256 * 3))
return null;
Color32[] LUT = new Color32[256];
for (int i = 0; i < 256; i++) {
LUT[i] = new Color32(0xff, data[i], data[i + 256], data[i + 512]);
}
return LUT;
} catch {
return null;
}
}
public static Color32[] LoadLUT(string file) {
try {
byte[] data; //= File.ReadAllBytes(file);
using (var stream = File.OpenRead(file))
{
var count = stream.Length;
data = new byte[count];
stream.Read(data, 0, (int)count);
}
if (data.Length != (256 * 3))
return null;
Color32[] LUT = new Color32[256];
for (int i = 0; i < 256; i++) {
LUT[i] = new Color32(0xff, data[i], data[i + 256], data[i + 512]);
}
return LUT;
} catch {
return null;
}
}
/// <summary>
/// Extracts the palette color LUT from DICOM dataset, valid for PALETTE COLOR <seealso cref="PhotometricInterpretation"/>
/// </summary>
/// <returns>Palette color LUT</returns>
/// <exception cref="DicomImagingException">Invalid photometric interpretation or plaette color lUT missing from database</exception>
private Color32[] GetPaletteColorLUT()
{
if (PhotometricInterpretation != PhotometricInterpretation.PaletteColor)
throw new DicomImagingException(
"Attempted to get Palette Color LUT from image with invalid photometric interpretation.");
if (!Dataset.Contains(DicomTag.RedPaletteColorLookupTableDescriptor)) throw new DicomImagingException("Palette Color LUT missing from dataset.");
int size = Dataset.Get<int>(DicomTag.RedPaletteColorLookupTableDescriptor, 0);
int first = Dataset.Get<int>(DicomTag.RedPaletteColorLookupTableDescriptor, 1);
int bits = Dataset.Get<int>(DicomTag.RedPaletteColorLookupTableDescriptor, 2);
var r = Dataset.Get<byte[]>(DicomTag.RedPaletteColorLookupTableData);
var g = Dataset.Get<byte[]>(DicomTag.GreenPaletteColorLookupTableData);
var b = Dataset.Get<byte[]>(DicomTag.BluePaletteColorLookupTableData);
// If the LUT size is 0, that means it's 65536 in size.
if (size == 0) size = 65536;
var lut = new Color32[size];
if (r.Length == size)
{
// 8-bit LUT entries
for (int i = 0; i < size; i++) lut[i] = new Color32(0xff, r[i], g[i], b[i]);
}
else
{
// 16-bit LUT entries... we only support 8-bit until someone can find a sample image with a 16-bit palette
// 8-bit entries with 16-bits allocated
int offset = 0;
// 16-bit entries with 8-bits stored
if (bits == 16) offset = 1;
for (int i = 0; i < size; i++, offset += 2) lut[i] = new Color32(0xff, r[offset], g[offset], b[offset]);
}
return lut;
}
/// <summary>
/// Save color look-up table to file.
/// </summary>
/// <param name="path">File name.</param>
/// <param name="lut">Look-up table to save.</param>
public static void SaveLUT(string path, Color32[] lut)
{
if (lut.Length != 256) return;
var file = IOManager.CreateFileReference(path);
using (var fs = file.Create())
{
for (var i = 0; i < 256; i++) fs.WriteByte(lut[i].R);
for (var i = 0; i < 256; i++) fs.WriteByte(lut[i].G);
for (var i = 0; i < 256; i++) fs.WriteByte(lut[i].B);
}
}
