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javaandroidopencvimagefilter

How to set color effect on document(image) using OpenCV(java)


currently, I'm working on a document scanner project who captures and filter document with different effects and color but I'm a beginner to work with OpenCV.

but, now I understand how medianBlurFilter , gaussianBlurFilter , cannyFilter and bilateralFilter works.

just I am starting to do this type of filter with the use of OpenCV but I can't understand how to achieve this.

Input :

enter image description here

How to achieve this?:

enter image description here

enter image description here


Solution

  • //bitmap is a normal document image
    
            Bitmap newB = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
            Canvas canvas = new Canvas(newB);
            canvas.drawColor(Color.argb(sp,255, 0, 0));
    
            Mat src = new Mat();
            Utils.bitmapToMat(bitmap, src);
    
            Mat dst = new Mat();
            Utils.bitmapToMat(newB, dst);
    
            Core.addWeighted(src, 1f, dst, 0.5f, 0.5, dst);
    
    
    //bitmapNew is a filtered document image
    
            Bitmap bitmapNew = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
            Utils.matToBitmap(dst, bitmapNew);