public static float DecodeCheckPSNR(string filename, Image <Rgba32> original)
{
using FileStream fs = File.OpenRead(filename);
var ktx = KtxFile.Load(fs);
var decoder = new BcDecoder();
using var img = decoder.Decode(ktx);
var pixels = original.GetPixelSpan();
var pixels2 = img.GetPixelSpan();
return(ImageQuality.PeakSignalToNoiseRatio(pixels, pixels2, true));
}
public ImageInfo Load(Stream input)
{
// Load Ktx file
var ktxFile = KtxFile.Load(input);
// Prepare main image data
var imageData = ktxFile.MipMaps[0].Faces[0].Data;
var imageFormat = (int)ktxFile.header.GlInternalFormat;
var size = new Size((int)ktxFile.header.PixelWidth, (int)ktxFile.header.PixelHeight);
// Prepare mip maps
return(new ImageInfo(imageData, imageFormat, size)
{
MipMapData = ktxFile.MipMaps.Skip(1).Select(x => x.Faces[0].Data).ToArray()
});
}
/// <summary>
/// Read a Ktx or a Dds file from a stream and decode it.
/// </summary>
public Image <Rgba32>[] DecodeAllMipMaps(Stream inputStream)
{
var position = inputStream.Position;
try {
if (inputStream is FileStream fs)
{
var extension = Path.GetExtension(fs.Name).ToLower();
if (extension == ".ktx")
{
KtxFile file = KtxFile.Load(inputStream);
return(DecodeAllMipMaps(file));
}
else if (extension == ".dds")
{
DdsFile file = DdsFile.Load(inputStream);
return(DecodeAllMipMaps(file));
}
}
bool isDDS = false;
using (var br = new BinaryReader(inputStream, Encoding.UTF8, true)) {
var magic = br.ReadUInt32();
if (magic == 0x20534444U)
{
isDDS = true;
}
}
inputStream.Seek(position, SeekOrigin.Begin);
if (isDDS)
{
DdsFile dds = DdsFile.Load(inputStream);
return(DecodeAllMipMaps(dds));
}
else
{
KtxFile ktx = KtxFile.Load(inputStream);
return(DecodeAllMipMaps(ktx));
}
}
catch (Exception) {
inputStream.Seek(position, SeekOrigin.Begin);
throw;
}
}
public void Bc4Decode()
{
using FileStream fs = File.OpenRead(@"../../../testImages/test_decompress_bc4_unorm.ktx");
KtxFile file = KtxFile.Load(fs);
Assert.True(file.Header.VerifyHeader());
Assert.Equal((uint)1, file.Header.NumberOfFaces);
BcDecoder decoder = new BcDecoder();
using var image = decoder.Decode(file);
Assert.Equal((uint)image.Width, file.Header.PixelWidth);
Assert.Equal((uint)image.Height, file.Header.PixelHeight);
using FileStream outFs = File.OpenWrite("decoding_test_bc4.png");
image.SaveAsPng(outFs);
}
public void LoadFromStream(Stream file)
{
tex2D = KtxFile.Load(file, false);
}
