/// <summary>
/// Captures a compressed video frame from the camera.
/// This method will try querying the image for a number of times until a valid image is received
/// or all the queries time out.
/// </summary>
/// <returns>A Bitmap.</returns>
/// <exception cref="TimeoutException">Thrown if the capture image query times out for every try.</exception>
public Bitmap ForceCaptureImage()
{
int minResponseTimeout = Math.Max(this.ResponseTimeout, this._currentImageResolution.Timeout / 2);
int maxResponseTimeout = Math.Max(this._currentImageResolution.Timeout, minResponseTimeout);
int numTries = 5;// should be > 1;
int increaseTimeout = (maxResponseTimeout - minResponseTimeout) / (numTries - 1);
this.ResponseTimeout = minResponseTimeout;
Bitmap frame = null;
for (int i = 0; i < numTries; i++)
{
try
{
frame = this.CaptureImage();
break;
}
catch (TimeoutException)
{
this.ResponseTimeout += increaseTimeout;
}
}
// Revert ResponseTimeout to the default value.
this.ResponseTimeout = _responseTimeout;
if (frame == null)
{
throw new TimeoutException("Image capture timed out for " + numTries + " tries.");
}
// Set current image resolution from the captured image.
ImageResolutions res = this._currentImageResolution.Resolution;
switch (frame.Width)
{
case 80:
res = ImageResolutions.Resolution80x64;
break;
case 160:
res = ImageResolutions.Resolution160x128;
break;
case 320:
res = ImageResolutions.Resolution320x240;
break;
}
if (this._currentImageResolution.Resolution != res)
{
this._currentImageResolution = new ImageResolution(res);
}
return(frame);
}
/// <summary>
/// Sets the camera capture resolution.
/// </summary>
/// <param name="resolution">A predefined image resolution to use when capturing images from the camera.</param>
/// <exception cref="ArgumentException">Thrown if ImageResolution is set to a value other than one of the predefined resolutions.</exception>
public void SetImageResolution(ImageResolutions resolution)
{
switch (resolution)
{
case ImageResolutions.Resolution80x64: this.SendCommand(SerialCommands.SetCaptureResolutionTo_80x64); break;
case ImageResolutions.Resolution160x128: this.SendCommand(SerialCommands.SetCaptureResolutionTo_160x128); break;
case ImageResolutions.Resolution320x240: this.SendCommand(SerialCommands.SetCaptureResolutionTo_320x240); break;
default: throw new ArgumentException("Invalid resolution");
}
this._currentImageResolution = new ImageResolution(resolution);
}
static ImageResolution()
{
_defaultResolution = new ImageResolution(ImageResolutions.Resolution160x128);
_defaultResTimeout = 1200;//ms
}
