open_ranger's profile - activity

How to make findChessboardCorners run faster? I have a chessboard image of size 3264x2448 when running on my Android 1.2

this way the text will be written as watermark,if the background happen to be white you wont be able to see anything.Als

Here is my version of putRotateText() void putRotateText(InputOutputArray img, const String& text, Point org,double

Dont know any text rendering engine yet so have to deal with openCV for now.

Here is my version of putRotateText() void putRotateText(InputOutputArray img, const String& text, Point org,double

Here is my version of putRotateText() void putRotateText(InputOutputArray img, const String& text, Point org,double

How to put rotated text in OpenCV ? OpenCV accepts void putText( InputOutputArray img, const String& text, Point o

Here Mat mat=(Mat_<uchar>(5,5)<<0,0,1,0,0, 0,2,2,2,0, 3,3,3,3,3, 0,4,4,4,0, 0,0,5,0,0); ostringstream m

Is there a way to display cv::Mat using __android_log_print() I know you can display a cv::Mat using cout << Mat &

What is the data structure looks like in Mat::data I am trying these code: Mat test1,test2; test1=Mat_<Vec3i>

I try to convert contour into Pixel and the output look funny.

void extractContour(Mat input){
    Mat temp=Mat::zeros(input.rows,input.cols,CV_8U);
    vector<vector<Point>> contour;
    findContours(input,contour,RETR_EXTERNAL,CHAIN_APPROX_NONE);
    for(int i=0;i<contour[0].size();i++){
    temp.at<Vec3b>(contour[0][i])=255;
    cout<<contour[0][i]<<"\t";
    }
    cout<<endl;
    imwrite("/home/wxh/Desktop/Photo/1.bmp",temp);
}

Any idea why is it deformed and in the wrong position?

☆⌒(*＾-゜)v THX!!

contour look strange I try to convert contour into Pixel and the output look funny. void extractContour(Mat input){

contour look strange I try to convert contour into Pixel and the output look funny. void extractContour(Mat input){

that thin circle is just the mouse cursor from the photo viewing software

I only made to look 3 steps ahead anything far away still left unconnected

Canny edge detection tends to leave small unconnected section between edges (usually just 1 pixel wide) is the any developed method in openCV to join those broken pieces? open and close method doesnt work very good if the kernel is too small it wont join all the section if too large it leave small truncks instead to skiny lines. Any ideas?

/usr/include/qt5: linker input file unused because linking not done My Qt Creator always give this warning I dont unders

Looks like you should use grayRefRoi = grayReference(refRectangle);

void joinEdges(Mat input){ int width=input.cols; int height=input.rows; const int dx[] = { 1, 1, 0, -1, -1, -1, 0, +1,

there is a extra space behind ".bmp"(+﹏+)~

I'm trying to utilising calcHist with the fowllowing code.

int channels[]={0,1,2};
int histSize[]={25,25,25};
float range[]={0,256};
const float* ranges[]={range,range,range};
printf("Ranges: %4.1d\t Type name: %s\t\n",0,typeid(ranges).name());
reference=imread("/home/wxh/Desktop/Photo/reference.bmp ",IMREAD_UNCHANGED);
calcHist(&reference,1,channels,noArray(),hist,3,histSize,ranges,true,false)

and the complier gives me the error message

OpenCV Error: Assertion failed (j < nimages) in histPrepareImages, file /home/wxh/opencv-3.2.0/modules/imgproc/src/histogram.cpp, line 148
terminate called after throwing an instance of 'cv::Exception'
  what():  /home/wxh/opencv-3.2.0/modules/imgproc/src/histogram.cpp:148: error: (-215) j < nimages in function histPrepareImages

Which part gone wrong?

Can't get correct parameter format for cv::calcHist I'm trying to utilising calcHist with the fowllowing code. int chan

Why increase threshold in HoughLinesP sometime yeild some lines? void onTrackbarSlide_1(int pos,void*){ threshold_1=

How to join broken edges from Canny Canny edge detection tends to leave small unconnected section between edges (usually

sometimes the error just right in front of me but I just cant see.

I'm trying to make a mask with black margin around edges so I type the follwoing code:

image=imread("/home/wxh/Desktop/Photo/1.jpg",IMREAD_UNCHANGED);
width=image.cols;
height=image.rows;
edge_left=image.cols*0.05;edge_top=image.rows*0.05;
mask=Mat::zeros(width,height,CV_8UC1);

printf("Mask rows:   %d\t cols: %d\t type:  %d\t channels: %d\t\n",mask.rows,mask.cols,mask.type(),mask.channels());
printf("Rectangle x: %d\t    y: %d\t width: %d\t height:   %d\t\n",edge_left,edge_top,width-2*edge_left,height-2*edge_top);

mask2=mask(Rect(edge_left,edge_top,width-2*edge_left,height-2*edge_top));

The console output give me this

Mask rows:   3264    cols: 2448  type:  0    channels: 1    
Rectangle x: 163        y: 122   width: 2938     height:   2204 
OpenCV Error: Assertion failed (0 <= roi.x && 0 <= roi.width && roi.x + roi.width <= m.cols && 0 <= roi.y && 0 <= roi.height && roi.y + roi.height <= m.rows) in Mat, file /home/wxh/opencv-3.2.0/modules/core/src/matrix.cpp, line 522
terminate called after throwing an instance of 'cv::Exception'
  what():  /home/wxh/opencv-3.2.0/modules/core/src/matrix.cpp:522: error: (-215) 0 <= roi.x && 0 <= roi.width && roi.x + roi.width <= m.cols && 0 <= roi.y && 0 <= roi.height && roi.y + roi.height <= m.rows in function Mat

Basiclly it says the rectangle roi is out of image range but I dont see how. Anyboady can point out the error for me?

Assertion failed roi out of range I'm trying to make a mask with black margin around edges so I type the follwoing code:

already declared namespace cv