问题
I was having a hard time loading training set from Ms Access database in to the main form that does the Face Recognition. I saved the training sets with their names and ID in to the database as a binary data with an OLE Object format.The method i used to change, save and read the data from the database and in to the training sets is
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;
}
}
}
The method that i use to store the converted byte data to the database is the following:
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();
}
}
The method that i use to Read this binary data is as follows:
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;
}
}
I have successfully saved the training sets/images as a binary data in to the database.The problem is when i load these training sets for Recognition.
// 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);
}
}
I am only getting the message in the catch when the the form loads even if there are faces saved in the database. I have used EigenObjectRecognizer and i will post the code if necessary.
回答1:
at the part of loading face, you did not save by face1, face2, face3 etc. So you can not load using;
LoadFaces = String.Format("face{0}.bmp", tf);
来源：https://stackoverflow.com/questions/16462306/c-sharp-emgu-cv-face-recognition-loading-training-sets-of-faces-saved-to-ac