ExtractFeatureAsync(IntPtr engine, Image image) =>
await Task.Run(async() =>
{
ImageInfo imageInfo = null;
var pSingleFaceInfo = IntPtr.Zero;
var pFaceFeature = IntPtr.Zero;
try
{
var asfFaces = await DetectFaceAsync(engine, image);
if (asfFaces.Code != 0)
{
return(new OperationResult <IEnumerable <byte[]> >(asfFaces.Code));
}
var faces = asfFaces.Data.Cast();
if (faces.FaceNum <= 0)
{
return(new OperationResult <IEnumerable <byte[]> >(null));
}
var features = new byte[faces.FaceNum][];
for (var i = 0; i < faces.FaceNum; i++)
{
var singleFaceInfo = faces.Faces[i];
pSingleFaceInfo = Marshal.AllocHGlobal(Marshal.SizeOf <SingleFaceInfo>());
Marshal.StructureToPtr(singleFaceInfo, pSingleFaceInfo, false);
imageInfo = ImageHelper.ReadBmp(image);
pFaceFeature = Marshal.AllocHGlobal(Marshal.SizeOf <AsfFaceFeature>());
var code = AsfHelper.ASFFaceFeatureExtract(engine, imageInfo.Width, imageInfo.Height,
imageInfo.Format, imageInfo.ImgData, pSingleFaceInfo, pFaceFeature);
if (code != 0)
{
return(new OperationResult <IEnumerable <byte[]> >(code));
}
var faceFeature = Marshal.PtrToStructure <AsfFaceFeature>(pFaceFeature);
var feature = new byte[faceFeature.FeatureSize];
Marshal.Copy(faceFeature.Feature, feature, 0, faceFeature.FeatureSize);
features[i] = feature;
}
return(new OperationResult <IEnumerable <byte[]> >(features));
}
finally
{
if (imageInfo != null)
{
Marshal.FreeHGlobal(imageInfo.ImgData);
}
if (pSingleFaceInfo != IntPtr.Zero)
{
Marshal.FreeHGlobal(pSingleFaceInfo);
}
if (pFaceFeature != IntPtr.Zero)
{
Marshal.FreeHGlobal(pFaceFeature);
}
}
});
/// <summary>
/// 提取最大人脸特征
/// </summary>
/// <param name="engine">引擎Handle</param>
/// <param name="image"></param>
/// <returns>保存人脸特征结构体指针</returns>
public static async Task <OperationResult <byte[]> > ExtractSingleFeatureAsync(IntPtr engine, Image image) =>
await Task.Run(async() =>
{
ImageInfo imageInfo = null;
var pSingleFaceInfo = IntPtr.Zero;
var pFaceFeature = IntPtr.Zero;
try
{
var asfFaces = await DetectFaceAsync(engine, image);
if (asfFaces.Code != 0)
{
return(new OperationResult <byte[]>(asfFaces.Code));
}
var faces = asfFaces.Data.Cast();
if (faces.FaceNum <= 0)
{
return(new OperationResult <byte[]>(null));
}
var singleFaceInfo = await GetBiggestFaceAsync(faces);
pSingleFaceInfo = Marshal.AllocHGlobal(Marshal.SizeOf <SingleFaceInfo>());
Marshal.StructureToPtr(singleFaceInfo, pSingleFaceInfo, false);
imageInfo = ImageHelper.ReadBmp(image);
pFaceFeature = Marshal.AllocHGlobal(Marshal.SizeOf <AsfFaceFeature>());
var code = AsfHelper.ASFFaceFeatureExtract(engine, imageInfo.Width, imageInfo.Height,
imageInfo.Format, imageInfo.ImgData, pSingleFaceInfo, pFaceFeature);
if (code != 0)
{
return(new OperationResult <byte[]>(code));
}
var faceFeature = Marshal.PtrToStructure <AsfFaceFeature>(pFaceFeature);
var feature = new byte[faceFeature.FeatureSize];
Marshal.Copy(faceFeature.Feature, feature, 0, faceFeature.FeatureSize);
return(new OperationResult <byte[]>(feature));
/*使用同一个引擎时，每次特征提取后的临时内存存储地址相同，后面的特征提取会覆盖之前的结果。
* 如要保存每次提取的特征，需要拷贝保存到单独的内存
*/
/*
* var localFeature = new AsfFaceFeature {Feature = Marshal.AllocHGlobal(feature.Length)};
* Marshal.Copy(feature, 0, localFeature.Feature, feature.Length);
* localFeature.FeatureSize = feature.Length;
*
* var pLocalFeature = Marshal.AllocHGlobal(Marshal.SizeOf<AsfFaceFeature>());
* Marshal.StructureToPtr(localFeature, pLocalFeature, false);
* return new OperationResult<IntPtr>(pLocalFeature);*/
}
finally
{
if (imageInfo != null)
{
Marshal.FreeHGlobal(imageInfo.ImgData);
}
if (pSingleFaceInfo != IntPtr.Zero)
{
Marshal.FreeHGlobal(pSingleFaceInfo);
}
if (pFaceFeature != IntPtr.Zero)
{
Marshal.FreeHGlobal(pFaceFeature);
}
}
});