我很难将训练集从 Ms Access 数据库加载到进行人脸识别的主窗体中。我将带有名称和 ID 的训练集作为具有 OLE 对象格式的二进制数据保存到数据库中。我用来更改、保存和读取数据库中的数据并保存到训练集中的方法是
private static byte[] ConvertImageToBytes(Image InputImage)
{
using (Bitmap BmpImage = new Bitmap(InputImage))
{
using (MemoryStream MyStream = new MemoryStream())
{
BmpImage.Save(MyStream, System.Drawing.Imaging.ImageFormat.Jpeg);
byte[] ImageAsBytes = MyStream.ToArray();
return ImageAsBytes;
}
}
}
我用来将转换后的字节数据存储到数据库的方法如下：
private void StoreData(byte[] ImageAsBytes,String NameStudent,String IDStudent)
{
if (DBConnection.State.Equals(ConnectionState.Closed))
DBConnection.Open();
try
{
//MessageBox.Show("Saving image at index : " + rowPosition);
using (OleDbCommand insert = new OleDbCommand(String.Format("Insert INTO
TrainingSet(rowPosition,StudentName,StudentID,StudentFace) values ('
{0}','{1}','{2}',@StudentFace)", rowPosition, NameStudent, IDStudent),
DBConnection))
{
OleDbParameter imageParameter = insert.Parameters.AddWithValue(@"StudentFace",
SqlDbType.Binary);
imageParameter.Value = ImageAsBytes;
imageParameter.Size = ImageAsBytes.Length;
int rowsAffected = insert.ExecuteNonQuery();
MessageBox.Show(String.Format("Data stored successfully in {0}
Row",rowsAffected));
}
rowPosition++;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
MessageBox.Show(ex.Message);
}
finally
{
RefreshDBConnection();
}
}
我用来读取此二进制数据的方法如下：
private Image ReadImageFromDB()
{
Image FetchedImg;
if (rowNumber >= 0)
{
byte[] FetchedImgBytes = (byte[])LocalDataTable.Rows[rowNumber]["StudentFace"];
MemoryStream stream = new MemoryStream(FetchedImgBytes);
FetchedImg = Image.FromStream(stream);
return FetchedImg;
}
else
{
MessageBox.Show("There are no images in the database yet.Please reconnect
or add some pictures.");
return null;
}
}
我已经成功地将训练集/图像作为二进制数据保存到数据库中。问题是当我加载这些训练集进行识别时。
// Declaring the variables=====trainingImages is where the training sets are
// loaded from the database NameLabels and IDLabels are text in the database
// and where name and Id of subject
//is saved.
List<Image<Gray,byte>> trainingImages = new List<Image<Gray,byte>>();
List<string> NameLables= new List<string>();
List<string> IDLables = new List<string>();
int ContTrain, NumNameLabels,NumIDLabels, t;
//The training sets from the database are loaded in to the facerecognizer code as
// follows
public FaceRecognizer()
{
InitializeComponent();
try
{
//Load previous trained and labels for each image from the database Here
RefreshDBConnection();
String[] NameLabels = (String[])LocalDataTable.Rows[rowNumber]["StudentName"];
NumNameLabels = Convert.ToInt16(NameLabels[0]);
String[] IDLabels = (String[])LocalDataTable.Rows[rowNumber]["StudentID"];
NumIDLabels = Convert.ToInt16(IDLabels[0]);
if (NumNameLabels == NumIDLabels)
{
ContTrain = NumNameLabels;
string LoadFaces;
// Converting the master image to a bitmap
Image imageFromDB;
Bitmap imageChangedToBitmap;
// Normalizing it to grayscale
Image<Gray, Byte> normalizedMasterImage;
for (int tf = 1; tf < NumNameLabels + 1; tf++)
{
imageFromDB = ReadImageFromDB();
//image loaded from the database is converted in to Bitmap and then
//convert the bitmap image in to Image<Gray,byte> for input to
//EigenObjectRecognizer(,,,)
imageChangedToBitmap = new Bitmap(imageFromDB);
normalizedMasterImage = new Image<Gray, Byte>(imageChangedToBitmap);
LoadFaces = String.Format("face{0}.bmp", tf);
trainingImages.Add(normalizedMasterImage);
//trainingImages.Add(new Image<Gray, byte>());
NameLables.Add(NameLabels[tf]);
IDLables.Add(IDLabels[tf]);
rowNumber = rowNumber + 1;
}
}
else
MessageBox.Show("There's a conflict between Name labels and id labels");
}
catch (Exception e)
{
MessageBox.Show("Nothing in the database, please add at least a
face.Train the database","Triained faces load",MessageBoxButtons.OK,
MessageBoxIcon.Exclamation);
}
}
即使在数据库中保存了面孔，我也只会在表单加载时收到消息。我使用了 EigenObjectRecognizer，如有必要，我将发布代码。