private static bool ConvertImage_Internal(KindleProfile profile, Bitmap bitmap, string outputFilePath, CancellationToken cancellationToken)
{
Bitmap bitmap24 = bitmap.Clone(new Rectangle(0, 0, bitmap.Width, bitmap.Height), PixelFormat.Format24bppRgb);
using (UnmanagedImage unmanagedImage = UnmanagedImage.FromManagedImage(bitmap24))
{
if (cancellationToken.IsCancellationRequested)
{
return false;
}
using (UnmanagedImage rotated = ImageBackend.RotateImage(profile, unmanagedImage))
{
if (cancellationToken.IsCancellationRequested)
{
return false;
}
using (UnmanagedImage resized = ImageBackend.ResizeImage(profile, rotated))
{
if (cancellationToken.IsCancellationRequested)
{
return false;
}
Bitmap quantized = ImageBackend.QuantizeImage(profile, resized);
if (cancellationToken.IsCancellationRequested)
{
return false;
}
Bitmap output = (quantized.PixelFormat == PixelFormat.Format8bppIndexed || quantized.PixelFormat == PixelFormat.Format4bppIndexed)
? quantized
: quantized.Clone(new Rectangle(0, 0, quantized.Width, quantized.Height), PixelFormat.Format8bppIndexed);
if (cancellationToken.IsCancellationRequested)
{
return false;
}
output.Save(outputFilePath);
return true;
}
}
}
}
public static bool ConvertImage(KindleProfile profile, Stream stream, string outputFilePath, CancellationToken cancellationToken)
{
Contract.Requires(profile != null);
Contract.Requires(stream != null);
Contract.Requires(!string.IsNullOrWhiteSpace(outputFilePath));
Contract.Requires(cancellationToken != null);
try
{
Bitmap bitmap = new Bitmap(stream);
return ConvertImage_Internal(profile, bitmap, outputFilePath, cancellationToken);
}
catch (Exception)
{
return false;
}
}
private static UnmanagedImage ResizeImage(KindleProfile profile, UnmanagedImage image)
{
UnmanagedImage output;
ResizeBicubic filter;
if (image.Width > image.Height)
{
double scalingFactor = (double)image.Width / profile.Width;
int newHeight = (int)Math.Floor((double)image.Height / scalingFactor);
filter = new ResizeBicubic(profile.Width, newHeight);
}
else
{
double scalingFactor = (double)image.Height / profile.Height;
int newWidth = (int)Math.Floor((double)image.Width / scalingFactor);
filter = new ResizeBicubic(newWidth, profile.Height);
}
output = filter.Apply(image);
return output;
}
private static UnmanagedImage RotateImage(KindleProfile profile, UnmanagedImage image)
{
if (image.Width > image.Height)
{
UnmanagedImage output;
RotateBicubic filter = new RotateBicubic(90);
output = filter.Apply(image);
return output;
}
return image;
}
private static Bitmap QuantizeImage(KindleProfile profile, UnmanagedImage image)
{
Bitmap output;
FloydSteinbergColorDithering dithering = new FloydSteinbergColorDithering();
dithering.ColorTable = profile.Palette;
output = dithering.Apply(image);
return output;
}
