huoshulei / sand

Using JNI to achieve Sobel operator image edge detection使用JNI实现Sobel算子图像边缘检测 https://github.com/Jomes/sand

sand

Sand is Android library that it is using JNI to achieve Sobel operator image edge detection. it's easy to build a picture like sand .

• 中文文档

Screenshot

Build

Step 1. Add the JitPack repository to your build file

add the JitPack maven to your project in root build.gradle

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

Step 2. Add module dependency build.gradle

 dependencies {
     	  compile 'com.github.Jomes:sand:v0.01'

 } 

That's it!

How to use

you can get Bitmap from SandPic class,you need to provide original Bitmap、threshold、pointNum。

Bitmap bitmap = SandPic.getInstance().tramform(originalBitmap,thre,pointNum);

there is a important tramform method in the SandPic class. it get pixels array from JNI.

public Bitmap tramform(Bitmap bitmap,int threshold,int ponitNum ){
        int width =  bitmap.getWidth();
        int height = bitmap.getHeight();
        Bitmap newImage = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(newImage);
        Paint paint = new Paint();
        paint.setAntiAlias(false);
        paint.setStyle(Paint.Style.STROKE);
        int pixels[] = new int [width*height];
        bitmap.getPixels(pixels,0,width,0,0,width,height);
        int[] generate = generate(pixels, width, height, threshold, ponitNum);
        for (int i = 0, n = generate.length; i + 1 < n; i += 2) {
                int x = generate[i]>0? generate[i]:0;
                int y = generate[i+1] >0?generate[i+1]:0 ;
                int color = bitmap.getPixel(x,y);
                paint.setColor(color);
                canvas.drawCircle(x, y, 1, paint);
            }

        return newImage;
    }

License

Copyright 2017 jomeslu [email protected]

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.