a small problem, Object reference not set to an instance of an object

Bahar Jalali

hi
i want to run this source code but i can't;

here is code URL:
http://www.oliveragustin.com/background-subtraction-in-c-part-2/

and it's the source code :

var image = new Image(filename);

// threshold values for each channel
var thresholds = new[] { new TRange(70, 255), new TRange(0, 255), new TRange(0, 255) };

Image[] grays = image.Convert().Split();

// threshold each channel
for (int i = 0; i < 3; i++)
{
grays[i]._ThresholdToZero(new Gray(thresholds[i].LowerValue));
grays[i]._ThresholdToZeroInv(new Gray(thresholds[i].UpperValue));
grays[i]._ThresholdBinary(new Gray(1), new Gray(255));
}

// merge the thresholded array of binary images above
var mask = grays[0].And(grays[1].And(grays[2]));

// result
var resultImage = image.Copy(mask);

my problem is this line :
var thresholds = new [] {new TRange(70,255), new TRange(0,255), new TRange(0,255)};

i don't know how must i define above line in c#! what is TRange? i defined it like the following code but it has error
"Object reference not set to an instance of an object";

public struct TRange

{

public int LowerValue, UpperValue;

public TRange(int x, int y)

{

LowerValue = x;

UpperValue = y;

}

// background subtraction in NewBGSubtraction

private void NewBGSubtraction(Bitmap filename, bool displayResult)

{

var image = new Image(filename);

// threshold values for each channel

var thresholds = new[] {new TRange(70, 255), new TRange(0, 255), new TRange(0, 255) };

Image[] grays = image.Convert().Split();

// threshold each channel

for (int i = 0; i < 3; i++)

{

grays[i]._ThresholdToZero(new Gray(thresholds[i].LowerValue));

grays[i]._ThresholdToZeroInv(new Gray(thresholds[i].UpperValue));

grays[i]._ThresholdBinary(new Gray(1), new Gray(255));

}

// merge the thresholded array of binary images above

var mask = grays[0].And(grays[1].And(grays[2]));

// result

var resultImage = image.Copy(mask);

pictureBox2.Image = resultImage.Bitmap;

}

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

live13y ago
Dude,

I am trying to implement the same piece of code but it doesn't work.
Can you send me your program?

I did this..

OpenFileDialog Openfile = new OpenFileDialog();
if (Openfile.ShowDialog() == DialogResult.OK)
{
//Load the Image
Image My_Image = new Image(Openfile.FileName);

//Display the Image
pictureBox1.Image = My_Image.ToBitmap();

}

var My_Image1 = new Image(Openfile.FileName);

// threshold values for each channel
var thresholds = new[] { new TRange(70, 255), new TRange(0, 255), new TRange(0, 255) };

Image[] grays = My_Image1.Convert().Split();

// threshold each channel
for (int i = 0; i < 3; i++)
{
grays[i]._ThresholdToZero(new Gray(thresholds[i].LowerValue));
grays[i]._ThresholdToZeroInv(new Gray(thresholds[i].UpperValue));
grays[i]._ThresholdBinary(new Gray(1), new Gray(255));
}

// merge the thresholded array of binary images above
var mask = grays[0].And(grays[1].And(grays[2]));

// result
var resultImage = My_Image1.Copy(mask);
pictureBox1.Image = resultImage.ToBitmap();

my email: [email protected]! Thanks
0
Bahar Jalali14y ago
it solved! my source code was correct but my variable "image" has defined in the top and i didn't attend it;
0
Bahar Jalali14y ago
no i searched about TRange but there isn't any solution in google!
0
Vulpes14y ago
It's not something I have any knowledge of but, judging by the author's first article, you're going to find the TRange class in the Emgu CV library:

http://www.oliveragustin.com/tag/background-subtraction/
0