Ask Your Question

jefferson-sep's profile - activity

2019-05-07 02:06:33 -0500 received badge  Popular Question (source)
2017-02-23 01:48:25 -0500 received badge  Famous Question (source)
2016-10-28 02:27:36 -0500 received badge  Famous Question (source)
2016-03-28 16:45:20 -0500 received badge  Notable Question (source)
2016-02-24 03:51:54 -0500 received badge  Notable Question (source)
2015-11-18 05:19:55 -0500 received badge  Popular Question (source)
2015-11-15 09:49:20 -0500 received badge  Popular Question (source)
2015-08-13 20:12:28 -0500 commented answer How to pass a ArrayList<MatOfPoint> for a jni C ++ function?

Thanks, but "Function 'Mat_to_vector_Point2f' could not be resolved", so what i need include on my .cpp ? Or i need implement this function ? @Yolteotl

2015-08-13 16:40:02 -0500 asked a question How to pass a ArrayList<MatOfPoint> for a jni C ++ function?

I am doing a project in Java with Android jni C ++. I have a function in C ++ with the following parameters:

C ++ function:

void rectify (vector <Point2f> & corners, Mat & img) {...}

In JAVA, call would be:

Mat image = Highgui.imread("img.png");
List <MatOfPoint> cornners =  new ArrayList<MatOfPoint>();;
Point b = new Point (real_x2, real_y2);
MatOfPoint ma = new MatOfPoint (b);
cornners.add(ma);
rectfy(image.getNativeObjAddr(), cornners)

public native "??" rectfy(long mat, "??" matofpoint);

With that, I wonder how will the function C ++ jni:

JNIEXPORT ?? JNICALL Java_ImageProcessingActivity_rectfy (JNIEnv * jobject, ?? cornners, inputMatAddress jlong)
2015-08-02 14:10:31 -0500 asked a question Can I use a code in C ++ OpenCV on an Android project?

Hello, i have a code OpenCV C++ that does some transformations at images. I would like to know if you can make an Android project that uses the camera to take a picture and then call the code I already have (in C ++) to perform the necessary transformations in the picture, after that, return the transformed image or save this image on phone.

Ps: This passage image can be directly or saving to SD card and open.

Can I use the code in C ++ I already own?

2015-06-04 23:14:40 -0500 asked a question Create an Android application OpenCV / C ++

Hello, I have a project in OpenCV C ++, and would like to pass it to Android, create an application with it. I wonder if you can use the code that I have in C ++, or need to convert it to Java? Thanks !!

2015-03-08 18:34:34 -0500 commented answer Detect a pixel with a specific color (OpenCV/C++)

Oh, that explains why I could only detect white or black -- ' Thanks

2015-03-08 18:00:00 -0500 commented answer Detect a pixel with a specific color (OpenCV/C++)

Thanks again Theodore! I'm using the follow code with image in example, but the output is just a black image. There's something wrong?

  Mat source = imread("chessOrange.png",1);
imshow("source", source);
Mat mask;
cv::Scalar lowerb = cv::Scalar(250, 125, 38);
cv::Scalar upperb = cv::Scalar(255, 129, 42);
cv::inRange(source, lowerb, upperb, mask);

imshow("mask", mask);
2015-03-08 12:53:37 -0500 asked a question Detect a pixel with a specific color (OpenCV/C++)

Hi, I'm trying to detect and map all pixels of a certain color. Then leave the pixels of that color. I have this image: image description

And I need to find the pixels orange (255,127,39). Then leave only the pixels of orange, like this: image description

I know the OpenCV has this function:

cv::findNonZero(src, vector_white_pixels);

but do not know if there is a similar function to specify color with pixels

Thanks for any help.

2015-03-07 16:39:20 -0500 commented question The program can't start because opencv_core2410d.dll is missing.
  1. Have you checked that the file exists in the designated directory?
  2. You already performed some opencv application?
2015-03-07 16:36:54 -0500 answered a question The program can't start because opencv_core2410d.dll is missing.
  1. Have you checked that the file exists in the designated directory?
  2. You already performed some opencv application?
2015-02-27 19:12:13 -0500 received badge  Organizer (source)
2015-02-27 19:01:23 -0500 received badge  Student (source)
2015-02-25 15:40:42 -0500 commented answer Image Transformation OpenCV/C++

Theodore, Thank you for your cooperation! I will try to adapt the code to work with images of this type: http://i.imgur.com/Z6KSOgU.jpg

2015-02-24 08:52:54 -0500 commented question Image Transformation OpenCV/C++

Yes, I'm trying it =)

2015-02-24 01:15:33 -0500 commented question Image Transformation OpenCV/C++

Thanks for the answer, but in this example, it inserts the coordinates of the points that form the corners. I meant to find automatically. But still helped because lack only able to determine the corners and I think I know how to do this, Tks!

2015-02-23 19:18:17 -0500 received badge  Editor (source)
2015-02-23 19:17:35 -0500 asked a question Image Transformation OpenCV/C++

Hello, I'm trying to perform a transformation, or perspective correction, on the image with the chess board features as follows:

image description

However, already tried in several places, including in the book Learning OpenCV and have not found a way to do this. If anyone can help me with this I thank you!

2015-02-18 00:02:23 -0500 received badge  Enthusiast
2015-02-16 21:38:01 -0500 commented answer Count pixels of a black and white image (OpenCV / C++ )

Thanks for the help!!!

2015-02-16 21:37:09 -0500 received badge  Scholar (source)
2015-02-16 16:48:07 -0500 asked a question Count pixels of a black and white image (OpenCV / C++ )

I am a beginner to opencv / C ++ and would like your help with a problem that seems simple. As an example, I have this image:

image description

... And would disregard the background, which will always be white, and the image is always black and white, leaving only the cloud to be able to count three things:

  1. The number of pixels of the figure (cloud only, disregarding the background).
  2. The number of white pixels. (cloud only)
  3. The number of black pixels. (cloud only)

I know that to achieve 2, with a subtraction with it the 3rd.

Thanks!

2015-01-07 21:34:43 -0500 asked a question Perspective correction for quadrilateral objects.

Hello, I am trying to get the perspective transformation of the image, to get the next result looks like this:image description

The following steps in the tutorial that I'm following are: 1.Get the edge map. 2.Detect lines with Hough transform. 3.Get the corners by finding intersections between lines. 4.Check if the approximate polygonal curve has 4 vertices. 5.Determine top-left, bottom-left, top-right, and bottom-right corner. 6.Apply the perspective transformation.

The transformation work only with the image used in the tutorial. For while trying to retrieve the edges and points of interception, the results are these:image description

And I can only make the transformation priate the image has the 4 pieces, forming a quadrilateral object.

I am starting in OpenCV / C ++ and any help will be greatly appreciated. Thank U.

Tutorial link: http://opencv-code.com/tutorials/auto...

2014-12-31 12:44:54 -0500 received badge  Supporter (source)