public void EnsureLossLessRoundTrip()
{
using (var stream = GetResource("scary_face.bmp"))
using (var image = Image.FromStream(stream))
using (var bmp = new Bitmap(image))
{
var data = bmp.LockBits(
new Rectangle(Point.Empty, image.Size),
ImageLockMode.ReadWrite,
PixelFormat.Format24bppRgb);
var argbStride = image.Width * 4;
var rgbStride = image.Width * 3;
var dest = new byte[argbStride * image.Height];
var dest2 = new byte[rgbStride * image.Height];
var original = new byte[rgbStride * image.Height];
fixed(byte *originalPtr = original)
fixed(byte *destPtr = dest)
fixed(byte *dest2Ptr = dest2)
{
// Put the original 24bit RGB pixel data into an array for
// later validation.
Buffer.MemoryCopy(
(void *)data.Scan0, originalPtr,
original.Length, original.Length);
// Convert the source 24bit RGB pixel data to 32bit ARGB.
// This conversion is lossless.
LibYuv.RGB24ToARGB(
(byte *)data.Scan0, rgbStride,
destPtr, argbStride,
image.Width, image.Height);
// Convert the newly created 32bit ARGB back to the original
// 24bit RGB. This conversion is lossless.
LibYuv.ARGBToRGB24(
destPtr, argbStride,
dest2Ptr, rgbStride,
image.Width, image.Height);
}
// Ensure that the data survived the round trip.
CollectionAssert.AreEqual(original, dest2);
// And this is sanity check, to ensure that we're infact
// doing something.
CollectionAssert.AreNotEqual(original, dest);
bmp.UnlockBits(data);
}
}
private unsafe BitmapSource GetBitmapFromImage()
{
var captureData = k4a_image_get_buffer(this.image.Handle);
var captureSize = (int)this.image.Size;
switch (image.Format)
{
case ImageFormat.ColorMJPG:
{
this.bitmapDecoder = new BitmapDecoder(this.imagingFactory, ContainerFormatGuids.Jpeg);
this.stream = new WICStream(this.imagingFactory, new DataPointer(captureData, captureSize));
this.bitmapDecoder.Initialize(this.stream, DecodeOptions.CacheOnLoad);
this.frame = this.bitmapDecoder.GetFrame(0);
this.formatConverter = new FormatConverter(this.imagingFactory);
formatConverter.Initialize(frame, PixelFormat.Format32bppPBGRA, BitmapDitherType.None, null, 0.0, BitmapPaletteType.Custom);
return(formatConverter);
}
case ImageFormat.ColorBGRA32:
return(new Bitmap(this.imagingFactory,
image.WidthPixels,
image.HeightPixels,
PixelFormat.Format32bppPBGRA,
new DataRectangle(captureData, image.StrideBytes),
captureSize));
case ImageFormat.IR16:
case ImageFormat.Depth16:
return(new Bitmap(this.imagingFactory,
image.WidthPixels,
image.HeightPixels,
PixelFormat.Format16bppGrayFixedPoint,
new DataRectangle(captureData, image.StrideBytes),
captureSize));
case ImageFormat.ColorNV12:
{
int textureWidth = this.image.WidthPixels;
int textureHeight = this.image.HeightPixels;
var imagePixels = textureWidth * textureHeight;
var nv12Span = new Span <byte>(captureData.ToPointer(), captureSize);
var nv12ySpan = nv12Span.Slice(0, imagePixels);
var nv12uvSpan = nv12Span.Slice(nv12ySpan.Length, (int)(imagePixels * 0.5));
var bitmap = new Bitmap(this.imagingFactory,
image.WidthPixels,
image.HeightPixels,
PixelFormat.Format32bppPBGRA,
BitmapCreateCacheOption.CacheOnLoad);
using (var bitmapLock = bitmap.Lock(BitmapLockFlags.Write))
{
var ptr = (byte *)bitmapLock.Data.DataPointer.ToPointer();
fixed(byte *yptr = nv12ySpan)
fixed(byte *uvptr = nv12uvSpan)
{
_ = LibYuv.NV12ToARGB(yptr, textureWidth, uvptr, textureWidth, ptr, textureWidth * 4, textureWidth, textureHeight);
}
}
return(bitmap);
}
case ImageFormat.ColorYUY2:
{
int textureWidth = this.image.WidthPixels;
int textureHeight = this.image.HeightPixels;
var imagePixels = textureWidth * textureHeight;
var yuv2Span = new Span <byte>(captureData.ToPointer(), captureSize);
var bitmap = new Bitmap(this.imagingFactory,
image.WidthPixels,
image.HeightPixels,
PixelFormat.Format32bppPBGRA,
BitmapCreateCacheOption.CacheOnLoad);
using (var bitmapLock = bitmap.Lock(BitmapLockFlags.Write))
{
var ptr = (byte *)bitmapLock.Data.DataPointer.ToPointer();
fixed(byte *yuv2ptr = yuv2Span)
{
_ = LibYuv.YUY2ToARGB(yuv2ptr, textureWidth * 2, ptr, textureWidth * 4, textureWidth, textureHeight);
}
}
return(bitmap);
}
case ImageFormat.Custom8:
case ImageFormat.Custom16:
case ImageFormat.Custom:
default:
throw new NotImplementedException($"Format not implemented: {image.Format}.");
}
}
