Databases
StackOverflow2013
Postsdbo
POWhat’s the point of desaturation and equalization in face detection?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhat’s the point of desaturation and equalization in face detection?
    primarykey
    data
    text
    <p>When I play the face detection code, I get some confusion. When I comment these two sentences: </p> <pre><code>//cvtColor( frame, frame_gray, CV_BGR2GRAY ); //equalizeHist( frame_gray, frame_gray ); </code></pre> <p>the result is still the same, which means Opencv (detectMultiScale) can still successfully find people’s face. I am thinking that what’s the point of changing colour-image to gray-image, and then getting the histogram of the gray-image?</p> <p>I attach part of the code as follows:</p> <pre><code>while (cvWaitKey(10) &lt; 0) { Mat frame = cvQueryFrame( capture ); // get the next frame of video cvtColor( frame, frame_gray, CV_BGR2GRAY ); equalizeHist( frame_gray, frame_gray ); face_cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, Size(30, 30) ); // Detect faces for( int i = 0; i &lt; faces.size(); i++ ) // for each face found { Point center( faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5 ); // location of this face ellipse( frame, center, Size( faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar( 255, 0, 255 ), 4, 8, 0 ); // draw ellipse around this face} imshow( "faces", frame); } ///////////////////////////////////////////////////////// ////////////////////////////////////////////////////////// </code></pre> <p>OR:</p> <pre><code>while (cvWaitKey(10) &lt; 0) { Mat frame = cvQueryFrame( capture ); // get the next frame of video //cvtColor( frame, frame_gray, CV_BGR2GRAY ); //equalizeHist( frame_gray, frame_gray ); face_cascade.detectMultiScale( frame, faces, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, Size(30, 30) ); // Detect faces for( int i = 0; i &lt; faces.size(); i++ ) // for each face found { Point center( faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5 ); // location of this face ellipse( frame, center, Size( faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar( 255, 0, 255 ), 4, 8, 0 ); // draw ellipse around this face} imshow( "faces", frame); } ////////////////////////////////////////////// </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USEmre
    1. USuser1893101
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWhat’s the point of desaturation and equalization in face detection?
      1. This table or related slice is empty.
      1. VTDownMod
    2. VO
      singulars
      1. POWhat’s the point of desaturation and equalization in face detection?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POWhat’s the point of desaturation and equalization in face detection?
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. COYou might get better responses if you tag your question appropriately with the library/api/platform you are using here. If you're using the OpenCV library, tag your question with that.
      singulars
      1. POWhat’s the point of desaturation and equalization in face detection?
      1. USTJ Thind
    2. COFor clarification, please indent your code correctly - it will make it easier for people to answer your question. I would suggest the edits myself, but I'm not sure about whether the `}` at the end of the "draw ellipse..." comment should be on a new line. Also it will improve visibility of your question if you tag it with both language and the particular detection framework you're using.
      singulars
      1. POWhat’s the point of desaturation and equalization in face detection?
      1. USJeff
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload