Dilation and erosion in Android

Question

According to my research,dilation and erosion can be used to bridge the gap for a image after binarize the image.

I not sure if cvSmooth needs to be used or not.

Solution 1

Android has mostly the same functions has the documented C++/Python, so all you need to do is find which class they belong to, in this case, Imgproc:

Imgproc.erode(mInput, mInput, Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(2,2)));        

Imgproc.dilate(mInput, mInput, Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(2, 2)));

Solution 2

You do have erosion and dilation in OpenCV. What you are looking for to "brige the gap" is probably what is called a closure, i.e. a dilatation followed by an erosion. It can be done using a single call to morphologyEx function. It could be an "opening", depending if you want to erode the white or black parts.

Comments

[CTZStef]

I don't know anything about OpenCV on Android, but I know that smoothing has nothing to do with morphological operations such as dilation and erosion. You will probably have first to obtain your binary image using cvTresh though (or the equivalent on Android).

[Hua Er Lim]

CTZStef,can i know how to use cvTresh to obtain the binary image?Before this,i use my own method to obtain the binary image and the effect is not good.

[CTZStef]

I guess you will find everything you need (e.g. documentation) here : code.opencv.org/projects/opencv/wiki/OpenCV4Android

[Hua Er Lim]

remi,i think you are right,i want to use dilation followed by erosion.Because i am new to android,can you give an example on how to code it for android?Thanks.

[Hua Er Lim]

remi,and can you tell me how to control wan erode the white or block parts?Thanks in advanced.

[remi]

erode the black = dilate the white. You have to do a simple test, you cannot change that, I dont remember what is decided in OpenCV implementation. As for Android samples, I only use C++/python bindings, but it should be straightforward, shouldn't it?