Develop Reference

How to set a extracted gif image to a picturebox in C#? [duplicate]

I want to show a frame of a gif image. I searched and found that the following code should work, but it doesn't work. it detects the number of frames correctly but it shows the whole frames of gif instead of the specified frame. thanks everybody.
Image[] frames = new Image[36];
Image GG = Image.FromFile(#"C:\Users\Administrator\TEST C#\TEST2frame2\chef.gif");
FrameDimension dimension = new FrameDimension(GG.FrameDimensionsList[0]);
// Number of frames
int frameCount = GG.GetFrameCount(dimension);
label1.Text = frameCount.ToString();
// Return an Image at a certain index
GG.SelectActiveFrame(dimension, 1);
frames[1] = ((Image)GG.Clone());
pictureBox1.Image = frames[1];

Use your own code up until the call of SelectActiveFrame() and after that change to this lines:
frames[0] = new Bitmap(GG);
pictureBox1.Image = frame[0];
This should do the trick. Please do not forget do dispose the created Images.

Oh it works, but not as you expect it to.
When you set an active frame of a gif image it actually restarts its animation from that frame. You have to stop it when you change a frame, by setting the pictureBox.IsEnabled to false, for instance. Try the following code
private Image img;
public Form1()
{
InitializeComponent();
img = Image.FromFile(#"C:\Users\Administrator\TEST C#\TEST2frame2\chef.gif");
pictureBox1.Image = img;
}
private void button1_Click(object sender, EventArgs e)
{
var dim = new FrameDimension(img.FrameDimensionsList[0]);
img.SelectActiveFrame(dim, 1);
pictureBox1.Enabled = false;
}
Try pressing the button in different moments and you will see that the active image frame will change.

Override Picturbox OnPaint Event to Rotate the Image -Create Custom Picturebox

I want to create a custom control or override the pictuebox's onpaint event such that i get access to the image before its drawn in the picturbox,so that i can rotate the image.
I know that i can do something like this
private void pictureBox1_Paint(object sender, PaintEventArgs e) {
e.Graphics.DrawRectangle(Pens.Black, new Rectangle(10, 10, 20, 20));
}
How to get access to the image and how to create a custom control.

Here is a quick example of a subclass: It hides the original Image property and replaces it with one that does a rotation before assigning it:
class RotatedPictureBox : PictureBox
{
private Image image;
public new Image Image {
get { return image; } // ?? you may want to undo the rotation here ??
set {
Bitmap bmp = value as Bitmap ;
// use the rotation you need!
if ( bmp != null ) bmp.RotateFlip(RotateFlipType.Rotate270FlipX);
image = bmp;
base.Image = Image;
}
}
}
public RotatedPictureBox ()
{
}
}
Caveat: Assigning an Image seems to work but I didn't test it for all possible uses.. Known limitations
It doesn't rotate images assigned via ImageLocation.
I had a crash once, when assigning an image in the Designer, but can't reproduce.

IP Camera stop streaming after some time

I am working on one application where I want to use IP camera for displaying video streaming and and some other major operations on image captured by the IP Camera.
Libraries used in Camera capture
For Camera Capture : Emgu.CV Library
Below is the code which I am using in C#.
Variable Declaration
private Capture capture; //takes images from camera as image frames
private Emgu.CV.UI.ImageBox img; // Dynamic Picture Controls
private int nCam; // no of cameras
Code for Processing Image
private void ProcessFrame(object sender, EventArgs arg)
{
try
{
// Live Streaming Display
Image<Bgr, Byte> ImageFrame = capture.QueryFrame();
// If Ip camera try to reinitialize the IP camera
if(ImageFrame == null)
{
capture.Dispose();
capture = new Capture(URL);
ImageFrame = capture.QueryFrame();
}
ImageFrame = ImageFrame.Resize(img.Width, img.Height, Emgu.CV.CvEnum.INTER.CV_INTER_LINEAR);
img.Image = ImageFrame;
// Here I am doing some other operations like
// 1. Save Image captured from the IP Camera
// 2. Detect faces in Image
// 3. Draw Face markers on Image
// 4. Some database based on result of Face Detection
// 4. Delete image File
// continue Looping for other Ip Cameras
}
catch (NullReferenceException e)
{
}
}
Now, The Problem is after some time the QueryFrame() provide null value and camera Stop streaming.
Can any one tell me why this is happening?
How I can resolve this problem?
If any more information is needed Please Let me know.
Thanks in Advance.

Sorry about the delay but I have provide an example that works with several public IP cameras. It will need the EMGU reference replacing with your current version and the target build directory should be set to "EMGU Version\bin" alternatively extract it to the examples folder.
http://sourceforge.net/projects/emguexample/files/Capture/CameraCapture%20Public%20IP.zip/download
Rather than using the older QueryFrame() method it uses the RetrieveBgrFrame() method. It has worked reasonably well and I have had no null exceptions. However if you do replace the ProcessFrame() method with something like this
You should not be attempting to do any operations if the frame returned is Image is a nullable field and should not have a problem if _capture.RetrieveBgrFrame(); returns null if there is a problem then there is a bigger issue.
private void ProcessFrame(object sender, EventArgs arg)
{
//If you want to access the image data the use the following method call
//Image<Bgr, Byte> frame = new Image<Bgr,byte>(_capture.RetrieveBgrFrame().ToBitmap());
if (RetrieveBgrFrame.Checked)
{
Image<Bgr, Byte> frame = _capture.RetrieveBgrFrame();
//because we are using an autosize picturebox we need to do a thread safe update
if(frame!=null)
{
DisplayImage(frame.ToBitmap());
Image<Bgr, Byte> ImageFrame = frame.Resize(img.Width, img.Height, Emgu.CV.CvEnum.INTER.CV_INTER_LINEAR);
// Here I am doing some other operations like
// 1. Save Image captured from the IP Camera
// 2. Detect faces in Image
// 3. Draw Face markers on Image
// 4. Some database based on result of Face Detection
// 4. Delete image File
// continue Looping for other Ip Cameras
}
//else do nothing as we have no image
}
else if (RetrieveGrayFrame.Checked)
{
Image<Gray, Byte> frame = _capture.RetrieveGrayFrame();
//because we are using an autosize picturebox we need to do a thread safe update
if (frame != null) DisplayImage(frame.ToBitmap());
}
}
On a separate note your comment 'continue Looping for other Ip Cameras' may cause several issues. You should have a new Capture constructor for each camera camera you are using. How many camera are you using? and what public ip camera are you using so I can attempt to replicate the issue? The reason for the separate constructor is that ip cameras take a while to negotiate connections with and constantly Disposing of the original construct and replacing it will play havoc with the garbage collector and introduce no end if timing issues.
Cheers
Chris
[EDIT]
If your camera is returning null frames after a timeout period then I would check to see if there is an issue with the setup or maybe your connection is so slow it disconnects you to reduce lag to others there are various causes but this is not a code problem. You can use c# alone to acquire the data to a bitmap and then pass this to an Image type variable. There is a great article here:
http://www.codeproject.com/Articles/15537/Camera-Vision-video-surveillance-on-C
I've adapted this so you can use a HttpWebRequest as a final check to see if the stream is alive although there are still null exceptions that will be produced here:
using System.Net;
using System.IO;
string url;
private void ProcessFrame(object sender, EventArgs arg)
{
//***If you want to access the image data the use the following method call***/
//Image<Bgr, Byte> frame = new Image<Bgr,byte>(_capture.RetrieveBgrFrame().ToBitmap());
if (RetrieveBgrFrame.Checked)
{
Image<Bgr, Byte> frame = _capture.RetrieveBgrFrame();
//because we are using an autosize picturebox we need to do a thread safe update
if (frame != null)
{
DisplayImage(frame.ToBitmap());
}
else
{
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
// get response
WebResponse resp = req.GetResponse();
//get stream
Stream stream = resp.GetResponseStream();
if (!stream.CanRead)
{
//try reconnecting the camera
captureButtonClick(null, null); //pause
_capture.Dispose();//get rid
captureButtonClick(null, null); //reconnect
}
}
}
else if (RetrieveGrayFrame.Checked)
{
Image<Gray, Byte> frame = _capture.RetrieveGrayFrame();
//because we are using an autosize picturebox we need to do a thread safe update
if (frame != null) DisplayImage(frame.ToBitmap());
}
}
private void captureButtonClick(object sender, EventArgs e)
{
url = Camera_Selection.SelectedItem.ToString(); //add this
... the rest of the code
}
To display multiple webcams you would create a class to handle the Capture construct and processframe event. Ideally you would raise an purpose built event call that would include a camera identifier as the frameready event call does not call this. I have to make things easier created a form with as a MDI parent and opened an object to manage the capture variables and frame ready event. The Alpha version is available here:
http://sourceforge.net/projects/emguexample/files/Capture/CameraCapture%20Public%20IP%20Multipl%20Display%20Alpha.zip/download

How To Extract specific Frame using AForge Library

I'm trying to extract a specific frame from a video file. I have a frame that I want when I play a video file with the aforge library. I call a new frame event, and if the new frame matches my specific frame, then it shows me a message: "Frame Match". This specific frame randomly appears in a video file. Here is my code:
private void Form1_Load(object sender, EventArgs e)
{
IVideoSource videoSource = new FileVideoSource(#"e:\media\test\a.mkv");
playerControl.VideoSource = videoSource;
playerControl.Start( );
videoSource.NewFrame += new AForge.Video.NewFrameEventHandler(Video_NewFrame );
}
private void Video_NewFrame(object sender, AForge.Video.NewFrameEventArgs eventArgs)
{
//Create Bitmap from frame
Bitmap FrameData = new Bitmap(eventArgs.Frame);
//Add to PictureBox
pictureBox1.Image = FrameData;
//compare current frame to specific fram
if (pictureBox1.Image == pictureBox2.Image)
{
MessageBox.Show("Frame Match");
}
}
pictureBox2.image is a fixed frame that I want to match. This code is working fine when I play video files and extract new frames, but I am unable to compare new frames to specific frames. Please guide me on how to achieve this.

You can take a look at:
https://github.com/dajuric/accord-net-extensions
var capture = new FileCapture(#"C:\Users\Public\Videos\Sample Videos\Wildlife.wmv");
capture.Open();
capture.Seek(<yourFrameIndex>, SeekOrigin.Begin);
var image = capture.ReadAs<Bgr, byte>();
or you can use standard IEnumerable like:
var capture = new FileCapture(#"C:\Users\Public\Videos\Sample Videos\Wildlife.wmv");
capture.Open();
var image = capture.ElementAt(<yourFrameIndex>); //will actually just cast image
Examples are included.
moved to: https://github.com/dajuric/dot-imaging

As far as I can understand your problem the issue is that you can't compare image to image this way. I think you will find that the way to do this is to build a histogram table and then compare image histograms.
Some of the related things to look into are:
how to compare two images
image comparer class form VS 2015 unit testing
The second one is from unit testing library so not sure of performance (haven't tried myself yet)

MediaLibrary.SavePicture fails when fed with a used stream

I need to save the photo that was captured with the CameraCaptureTask, in the Media Library of the phone, and at the same time I want to show this photo in an Image control. The thing is that I first try to rotate the image by accessing its Exif data, so as it appears with the correct orientation in the Image control.
private void cameraTask_Completed(object sender, PhotoResult e)
{
if (e.TaskResult == TaskResult.OK)
{
int angle = GetAngleFromExif(e.ChosenPhoto);
WriteableBitmap currentImage = DecodeImage(e.ChosenPhoto, angle);
photoImage.Source = currentImage;
MediaLibrary medialibrary = new MediaLibrary();
medialibrary.SavePicture("test.jpg", e.ChosenPhoto);
}
}
The code crashes in the last line, with the error:
Value does not fall within the expected range.
What is possibly going wrong here?
Thank you in advance.

Before calling the SavePicture method, you should set the Stream back at the beginning, like this:
e.ChosenPhoto.Seek(0, System.IO.SeekOrigin.Begin);