Example of using colorToHSV() and HSVToColor(), convert between argb color and HSV components.

• public static void colorToHSV (int color, float[] hsv)
  Convert the argb color to its HSV components. hsv[0] is Hue [0 .. 360] hsv[1] is Saturation [0...1] hsv[2] is Value [0...1]
• public static int HSVToColor (int alpha, float[] hsv)
  Convert HSV components to an ARGB color. The alpha component is passed through unchanged. hsv[0] is Hue [0 .. 360] hsv[1] is Saturation [0...1] hsv[2] is Value [0...1] If hsv values are out of range, they are pinned.

it's a example to convert a bitmap from argb color to HSV by calling colorToHSV() and convert back from HSV to argb by calling HSVToColor(). Refer the convertColorHSVColor(Bitmap src) method in the code.

package com.example.androidcolor;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.widget.ImageView;

public class MainActivity extends Activity {

 ImageView imgSource, imgTarget;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imgSource = (ImageView)findViewById(R.id.imgsource);
        imgTarget = (ImageView)findViewById(R.id.imgtarget);
        
        //Load bitmap from internet
        String onLineImgSource = "http://goo.gl/yxNeG";
        URL urlImgSource;
        
  try {
   urlImgSource = new URL(onLineImgSource);
   new MyNetworkTask(imgSource, imgTarget)
    .execute(urlImgSource);
  } catch (MalformedURLException e) {
   e.printStackTrace();
  }
        
    }
    
    private class MyNetworkTask extends AsyncTask<URL, Void, Bitmap>{
     
     ImageView ivSource, ivTarget;
     
     public MyNetworkTask(ImageView iSource, ImageView iTarget){
      ivSource = iSource;
      ivTarget = iTarget;
     }

  @Override
  protected Bitmap doInBackground(URL... urls) {
   Bitmap networkBitmap = null;
      
      URL networkUrl = urls[0]; //Load the first element
      try {
       networkBitmap = BitmapFactory.decodeStream(
         networkUrl.openConnection().getInputStream());
      } catch (IOException e) {
       e.printStackTrace();
      }

      return networkBitmap;
  }

  @Override
  protected void onPostExecute(Bitmap result) {
   ivSource.setImageBitmap(result);
   ivTarget.setImageBitmap(convertColorHSVColor(result));
  }

    }
    
    //Convert Bitmap from Color to HSV, then HSV to Color
    private Bitmap convertColorHSVColor(Bitmap src){

     int w = src.getWidth();
     int h = src.getHeight();
     
     int[] mapSrcColor = new int[w * h];
     int[] mapDestColor= new int[w * h];
     float[] pixelHSV = new float[3];
     /*
      * pixelHSV[0] : Hue (0 .. 360) 
      * pixelHSV[1] : Saturation (0...1) 
      * pixelHSV[2] : Value (0...1)
      */

     src.getPixels(mapSrcColor, 0, w, 0, 0, w, h);
     /*
      * getPixels (int[] pixels, int offset, int stride, int x, int y, int width, int height)
      * - Returns in pixels[] a copy of the data in the bitmap. Each value is a packed int representing a Color. 
      * 
      * pixels: The array to receive the bitmap's colors
      * offset: The first index to write into pixels[]
      * stride: The number of entries in pixels[] to skip between rows (must be >= bitmap's width). Can be negative.
      * x:  The x coordinate of the first pixel to read from the bitmap
      * y:  The y coordinate of the first pixel to read from the bitmap
      * width: The number of pixels to read from each row
      * height: The number of rows to read
      * 
      */
     
     int index = 0;
        for(int y = 0; y < h; ++y) {
            for(int x = 0; x < w; ++x) {    
                
                //Convert from Color to HSV
                Color.colorToHSV(mapSrcColor[index], pixelHSV);

                //Convert back from HSV to Color
                mapDestColor[index] = Color.HSVToColor(pixelHSV);
                
                index++;
            }
        }
        
        Config destConfig = src.getConfig();
        /*
         * If the bitmap's internal config is in one of the public formats, return that config, 
         * otherwise return null.
         */
        
        if (destConfig == null){
         destConfig = Config.RGB_565;
        }
     
        Bitmap newBitmap = Bitmap.createBitmap(mapDestColor, w, h, destConfig);
     
     return newBitmap;
    }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world"
        tools:context=".MainActivity" />
    <HorizontalScrollView 
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout 
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
            <ImageView
                android:id="@+id/imgsource"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
            <ImageView
                android:id="@+id/imgtarget"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"/>
        </LinearLayout>
    </HorizontalScrollView>

</LinearLayout>

Remark: Permission of "android.permission.INTERNET" is needed in this exercise to load Bitmap from internet.

Download the files.

Next:
- Represent hue, saturation, value components separately to understand HSV.