Android: modifying a certain color value of an image

First, we create a class called Image, which is mainly used to process graph-related operations. [Java] <span style = "font-size: 18px;"> package org.cn. tools; import java. io. IOException; import java. io. inputStream; import android. content. context; import android. graphics. bitmap; import android. graphics. matrix; import android. graphics. bitmap. config; import android. graphics. bitmapFactory; public class Image {public Bitmap bitmap; // Image resource object/*** obtain the Image by id * @ param context * @ param id */public Image (Context context, int id) {bitmap = BitmapFactory. decodeResource (context. getResources (), id);}/*** get the image by using the image file name, it is mainly used when an image is in the Asset directory * @ param context * @ param name image name * @ param scaleW Image Width scaling ratio * @ param scaleH Image Height scaling ratio * @ throws IOException * /public Image (Context context, string name, float scaleW, float scaleH) throws IOException {InputStream is = context. getAssets (). open (name); bitmap = BitmapFactory. DecodeStream (is); is. close (); bitmap = setScaleSize (bitmap, scaleW, scaleH);} public int getWidth () {return bitmap. getWidth ();} public int getHeight () {return bitmap. getHeight ();} /*** put the bitmap pixel value into the array * @ param x * @ param y * @ return */public int [] getPixel (int [] array, int x, int y) {bitmap. getPixels (array, 0, getWidth (), 0, 0, getWidth (), getHeight (); return array ;}/*** Create a Bitmap * @ param array * @ param w * @ param h * @ return */public Bitmap CreateImage (int [] array, int w, int h) {Bitmap image = Bitmap. createBitmap (array, w, h, Config. RGB_565); return image;}/*** image scaling * @ param bitmap * @ param arg0 * @ param arg1 * @ return */private Bitmap setScaleSize (Bitmap bitmap, float arg0, float arg1) {Matrix matrix = new Matrix (); matrix. postScale (arg0, arg1); bitmap = Bi Tmap. createBitmap (bitmap, 0, 0, getWidth (), getHeight (), matrix, true); return bitmap ;} /*** image memory recycling ** @ param Image * @ return */public static void free (image) {try {if (Image. bitmap! = Null) {if (image. bitmap. isRecycled () = false) {// if no memory image occupied by the image is recycled. bitmap. recycle (); if (image. bitmap. isRecycled () = true) {image. bitmap = null ;}} else {image. bitmap = null ;}} else {image. bitmap = null; // return null;} catch (Exception e) {e. printStackTrace () ;}// return image ;}</span> after the image processing class is created, we can perform operations in the activity to create an ImageAct. java. in this example, the white color is changed to red. [Java] <span style = "font-size: 18px;"> package org.cn; import java. io. IOException; import java. lang. character. unicodeBlock; import android. app. activity; import android. graphics. bitmap; import android. graphics. drawable. bitmapDrawable; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. view. window; import android. view. windowManager; import andro Id. view. windowManager. layoutParams; import android. widget. imageView; public class ImageAct extends Activity {Image image; int len; int red; int greed; int blue; int apla; int pix;/** Called when the activity is first created. * // @ Override public void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main); try {image = new Image (this, "Alfa_Romeo _ 8C_Competizione_Detail.png ", 1, 1); len = image. getWidth () * image. getHeight (); int [] imageARGB = new int [len]; int [] newimage = new int [len]; image. getPixel (imageARGB, 0, 0); for (int I = 0; I <image. getHeight (); I ++) for (int j = 0; j <image. getWidth (); j ++) {if (imageARGB [I * image. getWidth () + j]! = 0) {// apla = (imageARGB [I * image. getWidth () + j] & 0xaa000000)> 24); red = (imageARGB [I * image. getWidth () + j] & 0x00ff0000)> 16); greed = (imageARGB [I * image. getWidth () + j] & 0x0000ff00)> 8); blue = (imageARGB [I * image. getWidth () + j] & 0x000000ff); // int apla = (5*255/10) <24) | 0x00ffffff; if (red = 255 & greed = 255 & blue = 255) {red = 255; greed = 0; blue = 0; // p Ix = (red <16) | (greed <8) | blue) & apla;} pix = (red <16) | (greed <8) | blue; newimage [I * image. getWidth () + j] = pix;} else newimage [I * image. getWidth () + j] = imageARGB [I * image. getWidth () + j];} Bitmap bitmap = image. createImage (newimage, image. getWidth (), image. getHeight (); (ImageView) findViewById (R. id. imageView1 )). setImageBitmap (bitmap);} catch (IOException e) {// TODO Auto-gener Ated catch block e. printStackTrace () ;}}</span> OK. The preceding two classes can convert the white color in the image to red.