OpenCV 2.4:

    src.copyTo(dst(Rect(left, top, src.cols, src.rows)));

OpenCV 2.x:

    Mat dst_roi = dst(Rect(left, top, src.cols, src.rows));
    src.copyTo(dst_roi);

In addition or correction to above answers, if you want to copy a smaller region of open `Mat` to another `Mat`, you should do:


    src(Rect(left,top,width, height)).copyTo(dst);

Did work for me this way:

    Mat imgPanel(100, 250, CV_8UC1, Scalar(0));
    Mat imgPanelRoi(imgPanel, Rect(0, 0, imgSrc.cols, imgSrc.rows));
    imgSrc.copyTo(imgPanelRoi);
    
    imshow(&quot;imgPanel&quot;, imgPanel);
    waitKey();

I am using Opencv 2.4.9
Based on Andrey&#39;s answer.

I would like to display a custom font inside a UIWebView. I have already put the font in the plist under &quot;Fonts provided by application&quot;. The code in use:

            UIWebView *webView = [[UIWebView alloc] initWithFrame:myRect];
            NSURL *baseURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] bundlePath]];
            [webView loadHTMLString:html baseURL:baseURL];
            [self addSubview:webView];

where html is an NSString that has the following contents:

    &lt;html&gt;&lt;head&gt;
    &lt;style type=&quot;text/css&quot;&gt;
    @font-face {
    	font-family: gotham_symbol;
       	src: local(&#39;GOTHAMboldSymbol_0.tff&#39;), format(&#39;truetype&#39;) 
    } 
    body { 
     font-family: gotham_symbol;
    font-size: 50pt;
    }
    &lt;/style&gt;
    &lt;/head&gt;&lt;body leftmargin=&quot;0&quot; topmargin=&quot;0&quot;&gt;
    This is &lt;i&gt;italic&lt;/i&gt; and this is &lt;b&gt;bold&lt;/b&gt; and this is some unicode: &amp;#1101;
    &lt;/body&gt;&lt;/html&gt;

I&#39;m using iOS 4.2 so TTF should be supported. I&#39;d appreciate a bit of html/code that actually works.


Using custom font in a UIWebView

I have difficulty in removing border from a specific PrimeFaces `&lt;p:panelGrid&gt;`.

    &lt;p:panelGrid styleClass=&quot;companyHeaderGrid&quot;&gt;
        &lt;p:row&gt;
            &lt;p:column&gt;
                Some tags
            &lt;/p:column&gt;
            &lt;p:column&gt;
                Some tags
            &lt;/p:column&gt;
        &lt;/p:row&gt;
    &lt;/p:panelGrid&gt;

I have been able to remove border from the cells with:

    .companyHeaderGrid td {
        border: none;
    }

But

    .companyHeaderGrid {
        border: none;
    }

Does not work.


How to remove border from specific PrimeFaces p:panelGrid?

I need to copy a `cv::Mat` image (source) to an ROI of another (Destination) `cv::Mat` image.

I found [this reference][1], but it seems that it does not work for my case.
Do you have any pointers how could I do this using the OpenCV C++ interface?


  [1]: https://stackoverflow.com/questions/7041181/equivalent-to-cvsetimageroi-in-the-opencv-c-interface

Copy an cv::Mat inside a ROI of another one

<p>I need to copy a <code>cv::Mat</code> image (source) to an ROI of another (Destination) <code>cv::Mat</code> image.</p>
<p>I found <a href="https://stackoverflow.com/questions/7041181/equivalent-to-cvsetimageroi-in-the-opencv-c-interface" target="_blank" rel="noopener noreferrer">this reference</a>, but it seems that it does not work for my case.
Do you have any pointers how could I do this using the OpenCV C++ interface?</p>


When you allocate memory on the heap, the only limit is free RAM (or virtual memory). It makes Gb of memory. 

So why is stack size so limited (around 1 Mb)? What technical reason prevents you to create really big objects on the stack?

**Update**: My intent might not be clear, I *do not want* to allocate huge objects on the stack and I *do not need* a bigger stack. This question is just pure curiosity!

Why is stack memory size so limited?

I am trying to figure out how to write a macro that will pass both a string literal representation of a variable name along with the variable itself into a function.

For example given the following function.

    void do_something(string name, int val)
    {
       cout &lt;&lt; name &lt;&lt; &quot;: &quot; &lt;&lt; val &lt;&lt; endl;
    }

I would want to write a macro so I can do this:

    int my_val = 5;
    CALL_DO_SOMETHING(my_val);

Which would print out: `my_val: 5`

I tried doing the following:

    #define CALL_DO_SOMETHING(VAR) do_something(&quot;VAR&quot;, VAR);

However, as you might guess, the VAR inside the quotes doesn&#39;t get replaced, but is just passed as the string literal &quot;VAR&quot;. So I would like to know if there is a way to have the macro argument get turned into a string literal itself.


How to use Macro argument as string literal?

Why is this code gives an Debug Assertion Fail?
 
       std::string query;
       int ClientID = 666;
       query = &quot;select logged from login where id = &quot;;
       query.append((char *)ClientID);



Append an int to a std::string

In C++, is there a way to call a function on each element of a vector, without using a loop running over all vector elements? Something similar to a &#39;map&#39; in Python.

Calling a function on every element of a C++ vector

Since templates are defined within headers and compiler is able to determine if inlining a function is advantageous, does it make any sense? I&#39;ve heard that modern compilers know better when to inline a function and are ignoring `inline` hint.

---
edit: I would like to accept both answers, but this is not possible. To close the issue I am accepting **Sebastian Mach**&#39;s answer, because it received most votes and he is formally right, but as I mentioned in comments I consider **Puppy**&#39;s and **Component 10**&#39;s answers as correct ones too, from different point of view.

The problem is in C++ semantics, which is not strict in case of `inline` keyword and inlining. **Sebastian Mach** says &quot;write inline if you mean it&quot;, but what is actually meant by `inline` is not clear as it evolved from its original meaning to a directive that &quot;stops compilers bitching about ODR violations&quot; as **Puppy** says.

Does it make any sense to use inline keyword with templates?

How do you install and use OpenCV 2.4.3 under VC++ 2010 Express?

Installing OpenCV 2.4.3 in Visual C++ 2010 Express

I have an image of a coffee can with an orange lid position of which I want to find.
Here is it ![image][1].

gcolor2 utility shows HSV at the center of the lid to be (22, 59, 100).
The question is how to choose the limits of the color then? I tried min = (18, 40, 90) and max = (27, 255, 255), but have got unexpected ![result][2]

Here is the Python code:

    import cv

    in_image = &#39;kaffee.png&#39;
    out_image = &#39;kaffee_out.png&#39;
    out_image_thr = &#39;kaffee_thr.png&#39;

    ORANGE_MIN = cv.Scalar(18, 40, 90)
    ORANGE_MAX = cv.Scalar(27, 255, 255)
    COLOR_MIN = ORANGE_MIN
    COLOR_MAX = ORANGE_MAX

    def test1():
        frame = cv.LoadImage(in_image)
        frameHSV = cv.CreateImage(cv.GetSize(frame), 8, 3)
        cv.CvtColor(frame, frameHSV, cv.CV_RGB2HSV)
        frame_threshed = cv.CreateImage(cv.GetSize(frameHSV), 8, 1)
        cv.InRangeS(frameHSV, COLOR_MIN, COLOR_MAX, frame_threshed)
        cv.SaveImage(out_image_thr, frame_threshed)

    if __name__ == &#39;__main__&#39;:
        test1()




  [1]: http://i.stack.imgur.com/TGrDR.jpg
  [2]: http://i.stack.imgur.com/Sku73.png

Choosing the correct upper and lower HSV boundaries for color detection with`cv::inRange` (OpenCV)

I&#39;m writing for Android with OpenCV. I&#39;m segmenting an image similar to below using marker-controlled watershed, without the user manually marking the image. I&#39;m planning to use the regional maxima as markers.

`minMaxLoc()` would give me the value, but how can I restrict it to the blobs which is what I&#39;m interested in? Can I utilize the results from `findContours()` or cvBlob blobs to restrict the ROI and apply maxima to each blob?

![input image][1]


  [1]: http://i.stack.imgur.com/7EU8I.jpg

How to define the markers for Watershed in OpenCV?

I am using OpenCV (2.4) and Python (2.7.3) with a USB camera from Thorlabs (DC1545M).

I am doing some image analysis on a video stream and I would like to be able to change some of the camera parameters from my video stream.  The confusing thing is that I am able to change some of the camera properties but not all of them, and I am unsure of what I am doing wrong.

Here is the code, using the cv2 bindings in Python, and I can confirm that it runs:

    import cv2

   
    #capture from camera at location 0
    cap = cv2.VideoCapture(0)
    #set the width and height, and UNSUCCESSFULLY set the exposure time
    cap.set(3,1280)
    cap.set(4,1024)
    cap.set(15, 0.1)

    while True:
        ret, img = cap.read()
        cv2.imshow(&quot;input&quot;, img)
        #cv2.imshow(&quot;thresholded&quot;, imgray*thresh2)

        key = cv2.waitKey(10)
        if key == 27:
            break


    cv2.destroyAllWindows() 
    cv2.VideoCapture(0).release()

For reference, the first argument in the *cap.set()* command refers to the enumeration of the camera properties, listed below:

&lt;!-- NOTE Trick used to start numbering from 0, otherwise off by one due to markdown list formatting --&gt;

    0. CV_CAP_PROP_POS_MSEC Current position of the video file in milliseconds.
    1. CV_CAP_PROP_POS_FRAMES 0-based index of the frame to be decoded/captured next.
    2. CV_CAP_PROP_POS_AVI_RATIO Relative position of the video file
    3. CV_CAP_PROP_FRAME_WIDTH Width of the frames in the video stream.
    4. CV_CAP_PROP_FRAME_HEIGHT Height of the frames in the video stream.
    5. CV_CAP_PROP_FPS Frame rate.
    6. CV_CAP_PROP_FOURCC 4-character code of codec.
    7. CV_CAP_PROP_FRAME_COUNT Number of frames in the video file.
    8. CV_CAP_PROP_FORMAT Format of the Mat objects returned by retrieve() .
    9. CV_CAP_PROP_MODE Backend-specific value indicating the current capture mode.
    10. CV_CAP_PROP_BRIGHTNESS Brightness of the image (only for cameras).
    11. CV_CAP_PROP_CONTRAST Contrast of the image (only for cameras).
    12. CV_CAP_PROP_SATURATION Saturation of the image (only for cameras).
    13. CV_CAP_PROP_HUE Hue of the image (only for cameras).
    14. CV_CAP_PROP_GAIN Gain of the image (only for cameras).
    15. CV_CAP_PROP_EXPOSURE Exposure (only for cameras).
    16. CV_CAP_PROP_CONVERT_RGB Boolean flags indicating whether images should be converted to RGB.
    17. CV_CAP_PROP_WHITE_BALANCE Currently unsupported
    18. CV_CAP_PROP_RECTIFICATION Rectification flag for stereo cameras (note: only supported by DC1394 v 2.x backend currently)

(Please note, as commenter Markus Weber pointed out below, in OpenCV 4 you have to remove the &quot;CV&quot; prefix from the property name, eg 
`cv2.CV_CAP_PROP_FRAME_HEIGHT -&gt; cv2.CAP_PROP_FRAME_HEIGHT`)

My questions are:

**Is it possible to set camera exposure time (or the other camera parameters) through python/opencv?**


**If not, how would I go about setting these parameters?**  


Note: There is C++ code provided by the camera manufacturer showing how to do this, but I&#39;m not an expert (by a long shot) in C++ and would appreciate any python-based solution.

Thanks in advance!


Setting Camera Parameters in OpenCV/Python

I have this project where I need (on iOS) to detect simple geometric shapes inside an image.

![enter image description here][1]




After searching the internet I have concluded that the best tool for this is OpenCV. The thing is that up until two hours ago I had no idea what OpenCV is and I have never even remotely did anything involving image processing. My main experience is JS/HTML,C#,SQL,Objective-C...

Where do I start with this?

I have found this [answer][2] that I was able to digest and by reading already other stuff, I understand that OpenCV should return an Array of shapes with the points/corners, is this true? Also how will it represent a circle or a half circle? 
Also what about the shape orientation?

Do you know of any Demo iOS project that can demonstrate a similar functionality? 


  [1]: http://i.stack.imgur.com/pKJN7.png
  [2]: https://stackoverflow.com/questions/9663841/how-to-extract-simple-geometric-forms-from-contours-in-opencv

How to detect simple geometric shapes using OpenCV

I am new to SQL, and what I needed to do was to combine 2 .mdf databases into one. I did that using SQL Server 2008 Manager - Tasks &gt; Import/Export tables.The tables and views were copied successfully, but there are no Stored procedures in the new database. Is there any way to do that?

SQL Server - copy stored procedures from one db to another

When a file is created (`FileSystemWatcher_Created`) in one directory I copy it to another. But When I create a big (&gt;10MB) file it fails to copy the file, because it starts copying already, when the file is not yet finished creating...  
This causes **Cannot copy the file, because it&#39;s used by another process** to be raised. ;(  
Any help?


    class Program
    {
        static void Main(string[] args)
        {
            string path = @&quot;D:\levan\FolderListenerTest\ListenedFolder&quot;;
            FileSystemWatcher listener; 
            listener = new FileSystemWatcher(path);
            listener.Created += new FileSystemEventHandler(listener_Created);
            listener.EnableRaisingEvents = true;
    
            while (Console.ReadLine() != &quot;exit&quot;) ;
        }
    
        public static void listener_Created(object sender, FileSystemEventArgs e)
        {
            Console.WriteLine
                    (
                        &quot;File Created:\n&quot;
                       + &quot;ChangeType: &quot; + e.ChangeType
                       + &quot;\nName: &quot; + e.Name
                       + &quot;\nFullPath: &quot; + e.FullPath
                    );
            File.Copy(e.FullPath, @&quot;D:\levan\FolderListenerTest\CopiedFilesFolder\&quot; + e.Name);
            Console.Read();
        }
    }

Wait Until File Is Completely Written

How do I copy a folder from remote to local host using `scp`?

I use `ssh` to log in to my server.  
Then, I would like to copy the remote folder `foo` to local `/home/user/Desktop`.

How do I achieve this?

How do I copy a folder from remote to local using scp?

I wonder whether copying a vector&lt;int&gt; I am copying the vector with its values (whereas this is not working with array, and deep copy need a loop or memcpy).

Could you hint to an explanation?

Regards 

std vector C++ -- deep or shallow copy

I am trying to use my Mac Terminal to scp a file from Downloads (phpMyAdmin I downloaded online) to my Amazon EC2 instance. 

The command I used was:
    
    scp -i myAmazonKey.pem phpMyAdmin-3.4.5-all-languages.tar.gz  hk22@mec2-50-17-16-67.compute-1.amazonaws.com:~/.

The error I got: 
**Warning: Identity file myAmazonKey.pem not accessible: No such file or directory.
Permission denied (publickey).
lost connection**

Both my myAmazonkey.pem and phpMyAdmin-3.4.5-all-languages.tar.gz are in Downloads, so then I tried 

    scp -i /Users/Hello_Kitty22/Downloads/myAmazonKey.pem /Users/Hello_Kitty22/Downloads/phpMyAdmin-3.4.5-all-languages.tar.gz  hk22@mec2-50-17-16-67.compute-1.amazonaws.com:~/.

and the error I got:
**Warning: Identity file /User/Hello_Kitty22/Downloads/myAmazonkey.pem not accessible: No such file or directory.
Permission denied (publickey).
lost connection**

Can anyone please tell me how to fix my problem?

p.s. there is a similar post: https://stackoverflow.com/questions/6558080/scp-secure-copy-to-ec2-instance-without-password
but it doesn&#39;t answer my question. 


Content Type	Original Author	Original Content on Stackoverflow
Question	theosem	View Question on Stackoverflow
Solution 1 - C++	Andrey Kamaev	View Answer on Stackoverflow
Solution 2 - C++	Mich	View Answer on Stackoverflow
Solution 3 - C++	Renato Aloi	View Answer on Stackoverflow

Copy an cv::Mat inside a ROI of another one

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Solution 3 - C++

How to remove border from specific PrimeFaces p:panelGrid?

Using custom font in a UIWebView

Attributions