DDS_Mytheral's profile - activity

So I have a bunch of data from MatLab in a 16bit format... Values like Red: 42676, Green: 60145, Blue: 38758 and I'm trying to convert it to something usable in OpenCV as my values coming back are like 238.38.

I'm at a bit of a loss how to make those numbers match up... Any idea's on how to convert the MatLab data would be appreciated.

edit: Is it as simple as dividing by 256?

So I've found contours but because of a lack on contrast in my image some of the contours I'm finding aren't what I'm expecting. So is there any way of editing a found contour?

I'm looking for a dot on an image and sometimes due to the lack of contrast it grabs most of the dot then proceeds to wrap around the rest of the image... Is there any way of manually fixing my contours?

The minval method is nice for showing a change but I just wanted some clarification. You said -28 would show up as 227 and I'm assuming a positive 28 would still show up as 28.

With HSV wouldn't you still need the average for the H, S & V values individually?

So I've been attempting some image manipulation and I've come across a problem which seems simple but I can't seem to wrap my head about.

How do you isolate a change in color?

Say you have a grey colored dot with a value of Red 100, Green 100, Blue 100

Then you put a blue overlay with values of R 4, G 10, B 251 with 50% opacity on that dot and end up with values of Red 72, Green 74, Blue 124

So the change is roughly Red -28, Green -26, Blue +24

The best Idea I have is to only take the positive values but even that seems wrong as R 0, G 0, B 24 is a far cry from R 4, G 10, B 251.

Is there a stupid easy function I'm missing or am I just over thinking it?

A quick Google search is coming up with the lack of a method for dealing with the pixels inside a contour.

Is there a preferred method for getting data out of a non-rectangle contour?

I have an image with a bunch of dots on it and they test various things like humidity and PH.

So I have my larger image split up into a grid and I want to evaluate each dot one by one.

Getting a submat is easy and even the threshold seems to work well but when I go to get the contours is where I have problem.

Thresholded Image

The contouring seems to "work" but instead of finding the big black dot it's finding one small contour that doesn't even show up when calling drawContours

public Mat findImageContours(Mat image)
{
    Mat intialImage = image.clone();

    /* Get contours from threshold image */
    List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
    Imgproc.findContours(intialImage, contours, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

    for (int i = 0; i < contours.size(); i++)
    {
        Scalar CONTOUR_COLOR = new Scalar(0, 255, 0);

        Log.e(TAG, "Contours count: " + contours.size());
        Imgproc.drawContours(intialImage, contours, -1, CONTOUR_COLOR);
    }

    contouredInit = intialImage.clone();
    return intialImage;
}

Any help is appreciated.

@berak The Row/Col incorrectly specified was an issue but it's still crashing with the same error... Updated above code.

So I'm trying to use the Reduce() function to get row and column summations but I've hit a snag. It's crashing and telling me that there is an unsupported combinations of formats.

Unsupported combination of input and output array formats in function void cv::reduce(cv::InputArray, cv::OutputArray, int, int, int)

I've looked at this thread: http://answers.opencv.org/question/36...

That says you have to specify CvType which I've done but I'm still encountering an error.

Does Reduce not work with 8UC3 images? Or is there something else I am missing?

Any help is appreciated.

OpenCV Error: Unsupported format or combination of formats (Unsupported combination of input and output array formats) in void cv::reduce(cv::InputArray, cv::OutputArray, int, int, int), file /hdd2/buildbot/slaves/slave_ardbeg1/50-SDK/opencv/modules/core/src/matrix.cpp, line 2365

E/org.opencv.core﹕ core::reduce_10() caught cv::Exception: /hdd2/buildbot/slaves/slave_ardbeg1/50-SDK/opencv/modules/core/src/matrix.cpp:2365: error: (-210) Unsupported combination of input and output array formats in function void cv::reduce(cv::InputArray, cv::OutputArray, int, int, int)

E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.android.BluetoothChat, PID: 6166
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.BluetoothChat/com.example.android.BluetoothChat.AnalysisActivity}: CvException [org.opencv.core.CvException: cv::Exception: /hdd2/buildbot/slaves/slave_ardbeg1/50-SDK/opencv/modules/core/src/matrix.cpp:2365: error: (-210) Unsupported combination of input and output array formats in function void cv::reduce(cv::InputArray, cv::OutputArray, int, int, int)
    ]
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: CvException [org.opencv.core.CvException: cv::Exception: /hdd2/buildbot/slaves/slave_ardbeg1/50-SDK/opencv/modules/core/src/matrix.cpp:2365: error: (-210) Unsupported combination of input and output array formats in function void cv::reduce(cv::InputArray, cv::OutputArray, int, int, int)
    ]
            at org.opencv.core.Core.reduce_0(Native Method)
            at org.opencv.core.Core.reduce(Core.java:6661)
            at com.example.android.BluetoothChat.TemplateMatching.findGrid(TemplateMatching.java:396)
            at com.example.android.BluetoothChat.TemplateMatching.runIt(TemplateMatching.java:660)
            at com.example.android.BluetoothChat.TemplateMatching.<init>(TemplateMatching.java:574)
            at com.example.android.BluetoothChat.AnalysisActivity.onCreate(AnalysisActivity.java:71)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            ... 10 more

Working like a charm. Thanks much.

For some reason I was thinking it was a separate package that needed to be imported.

I did look at that but when I get to the code I can't import org.opencv.core.Core.reduce. It does know org.opencv.core.Core but it's only seeing MinMaxLocResult under that.

So I know that C, C++ and Python have the reduce function: http://docs.opencv.org/modules/core/d...

But I can't seem to get it working on Android with OpenCV4Android. I'm not getting any autocomplete for it in Android Studio so I assume I need to import something or directly specify which package it's in.

Can anyone know what include it needs? Or perhaps a tutorial for it or otherwise just shine some light on this?

Basically it just adds up the number of pixels in each row and column. Generally you run a blackhat filter on the image then use sum segmentation mask to add up each non-transparent pixel. From that you can use those sums to form a grid.

Using Sum Segmentation in Matlab you can turn this:

Into this:

Which is my first step in creating a best fit grid for the dot array. Normally I'd just impose a grid over the dots but the dots positions are somewhat random as they are placed by hand. The fact they are placed by hand means I need to create a "Best Fit Grid" to properly segment the image.

So does OpenCV have a "Sum Segmentation" fuction or if not is there another way I can go about this?

So I'm attempting to get a BlackHat Morph of an image but after applying the Morph operation I'm getting a Blank image and I'm not sure why.

Code:

private coid convertToBlackHat( Mat passedImage )
    {
        // Create a structuring element (SE)
    int morph_size = 100;
    Mat element = Imgproc.getStructuringElement( Imgproc.MORPH_RECT, new Size( 2*morph_size + 1, 2*morph_size+1 ), new Point( morph_size, morph_size ) );

    Mat dst = new Mat(); // result matrix
    // Apply the specified morphology operation
    Imgproc.morphologyEx( passedImage, dst, MORPH_TOPHAT, element, Point(-1,-1));   


    mBlackhatOutput = dst.clone();
}

The image is a 24-Bit jpeg at 1920x1080 with 100px circles on it.