C#调整图片亮度和对比度

BitmapSource bitmap = null;
int degreeBrightness = ;
int degreeContrast = ;

private void SetBrightness(int degree)
{
degree = degree *  / ;
WriteableBitmap wb = new WriteableBitmap(bitmap);
uint[] PixelData = new uint[wb.PixelWidth * wb.PixelHeight];
wb.CopyPixels(PixelData,  * wb.PixelWidth, );
for (uint y = ; y < wb.PixelHeight; y++)
{
for (uint x = ; x < wb.PixelWidth; x++)
{
uint pixel = PixelData[y * wb.PixelWidth + x];
byte[] dd = BitConverter.GetBytes(pixel);
int B = (int)dd[] + degree;
int G = (int)dd[] + degree;
int R = (int)dd[] + degree;
if (B < ) B = ;
if (B > ) B = ;
if (G < ) G = ;
if (G > ) G = ;
if (R < ) R = ;
if (R > ) R = ;
dd[] = (byte)B;
dd[] = (byte)G;
dd[] = (byte)R;
PixelData[y * wb.PixelWidth + x] = BitConverter.ToUInt32(dd, );
}
}
wb.WritePixels(new Int32Rect(, , wb.PixelWidth, wb.PixelHeight), PixelData,  * wb.PixelWidth, );
//this.image.Source = wb;
}
private void SetContrast(int degree)
{
double contrast = (100.0 + degree) / 100.0;
WriteableBitmap wb = new WriteableBitmap(bitmap);
uint[] PixelData = new uint[wb.PixelWidth * wb.PixelHeight];
wb.CopyPixels(PixelData,  * wb.PixelWidth, );
for (uint y = ; y < wb.PixelHeight; y++)
{
for (uint x = ; x < wb.PixelWidth; x++)
{
uint pixel = PixelData[y * wb.PixelWidth + x];
byte[] dd = BitConverter.GetBytes(pixel);
double B = (((double)dd[] /  - 0.5) * contrast + 0.5) * ;
double G = (((double)dd[] /  - 0.5) * contrast + 0.5) * ;
double R = (((double)dd[] /  - 0.5) * contrast + 0.5) * ;
if (B < ) B = ;
if (B > ) B = ;
if (G < ) G = ;
if (G > ) G = ;
if (R < ) R = ;
if (R > ) R = ;
dd[] = (byte)B;
dd[] = (byte)G;
dd[] = (byte)R;
PixelData[y * wb.PixelWidth + x] = BitConverter.ToUInt32(dd, );
}
}
wb.WritePixels(new Int32Rect(, , wb.PixelWidth, wb.PixelHeight), PixelData,  * wb.PixelWidth, );
//this.image.Source = wb;
}
private void SetCaptureImageCurrent(int degreeContrast, int degreeBrightness)
{
if (bitmap == null)
{
return;
}
WriteableBitmap wb = new WriteableBitmap(bitmap);
uint[] PixelData = new uint[wb.PixelWidth * wb.PixelHeight];
wb.CopyPixels(PixelData,  * wb.PixelWidth, );

if (degreeBrightness != )
{
degreeBrightness = degreeBrightness *  / ;
for (uint y = ; y < wb.PixelHeight; y++)
{
for (uint x = ; x < wb.PixelWidth; x++)
{
uint pixel = PixelData[y * wb.PixelWidth + x];
byte[] dd = BitConverter.GetBytes(pixel);
int B = (int)dd[] + degreeBrightness;
int G = (int)dd[] + degreeBrightness;
int R = (int)dd[] + degreeBrightness;
if (B < ) B = ;
if (B > ) B = ;
if (G < ) G = ;
if (G > ) G = ;
if (R < ) R = ;
if (R > ) R = ;
dd[] = (byte)B;
dd[] = (byte)G;
dd[] = (byte)R;
PixelData[y * wb.PixelWidth + x] = BitConverter.ToUInt32(dd, );
}
}
}

if (degreeContrast != )
{
double contrast = (100.0 + degreeContrast) / 100.0;
for (uint y = ; y < wb.PixelHeight; y++)
{
for (uint x = ; x < wb.PixelWidth; x++)
{
uint pixel = PixelData[y * wb.PixelWidth + x];
byte[] dd = BitConverter.GetBytes(pixel);
double B = (((double)dd[] /  - 0.5) * contrast + 0.5) * ;
double G = (((double)dd[] /  - 0.5) * contrast + 0.5) * ;
double R = (((double)dd[] /  - 0.5) * contrast + 0.5) * ;
if (B < ) B = ;
if (B > ) B = ;
if (G < ) G = ;
if (G > ) G = ;
if (R < ) R = ;
if (R > ) R = ;
dd[] = (byte)B;
dd[] = (byte)G;
dd[] = (byte)R;
PixelData[y * wb.PixelWidth + x] = BitConverter.ToUInt32(dd, );
}
}
}

wb.WritePixels(new Int32Rect(, , wb.PixelWidth, wb.PixelHeight), PixelData,  * wb.PixelWidth, );

PngBitmapEncoder pE = new PngBitmapEncoder();
pE.Frames.Add(BitmapFrame.Create(wb));
using (Stream stream = File.Create(SelectedImage))
{
pE.Save(stream);
}
Messenger.Default.Send(wb, "PatientImageView");
}