Android 图像处理 matrix ColorMatrix 旋转移动

目录(?)[+]

1. 一 显示打开图片
2. 二 Matrix操作
3. 三 Matrix处理的原理

前一篇文章讲述了Android拍照、截图、保存并显示在ImageView控件中,该篇文章继续讲述Android图像处理技术,主要操作包括:通过打开相册里的图片,使用Matrix对图像进行缩放、旋转、移动、对比度、亮度、饱和度操作,希望对大家有所帮助.

一. 显示打开图片

首先,设置activity_main.xml布局如下所示：

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1. <RelativeLayoutxmlns:android="http://schemas.android.com/apk/res/android"
2. xmlns:tools="http://schemas.android.com/tools"
3. android:id="@+id/container"
4. android:layout_width="match_parent"
5. android:layout_height="wrap_content"
6. tools:context="com.example.cangeimagetest.MainActivity"
7. tools:ignore="MergeRootFrame">
9. <LinearLayout
10. android:layout_width="match_parent"
11. android:layout_height="wrap_content"
12. android:orientation="vertical">
13. <Button
14. android:id="@+id/button1"
15. android:layout_width="match_parent"
16. android:layout_height="wrap_content"
17. android:text="选择图片"/>
18. <TextView
19. android:id="@+id/textView1"
20. android:layout_width="match_parent"
21. android:layout_height="wrap_content"
22. android:visibility="invisible"
23. android:text="原图显示"/>
24. <ImageView
25. android:id="@+id/imageView1"
26. android:layout_width="wrap_content"
27. android:layout_gravity="center_horizontal"
28. android:layout_height="wrap_content"/>
29. <TextView
30. android:id="@+id/textView2"
31. android:layout_width="match_parent"
32. android:layout_height="wrap_content"
33. android:visibility="invisible"
34. android:text="变化后的图片"/>
35. <ImageView
36. android:id="@+id/imageView2"
37. android:layout_gravity="center_horizontal"
38. android:layout_marginBottom="20dp"
39. android:layout_width="wrap_content"
40. android:layout_height="wrap_content"/>
41. </LinearLayout>
43. <LinearLayout
44. android:layout_width="match_parent"
45. android:layout_height="wrap_content"
46. android:orientation="horizontal"
47. android:layout_alignParentBottom="true">
48. <Button
49. android:id="@+id/button2"
50. android:layout_width="wrap_content"
51. android:layout_height="match_parent"
52. android:layout_weight="1"
53. android:text="缩小"/>
54. <Button
55. android:id="@+id/button3"
56. android:layout_width="wrap_content"
57. android:layout_height="match_parent"
58. android:layout_weight="1"
59. android:text="放大"/>
60. <Button
61. android:id="@+id/button4"
62. android:layout_width="wrap_content"
63. android:layout_height="match_parent"
64. android:layout_weight="1"
65. android:text="旋转"/>
66. <Button
67. android:id="@+id/button5"
68. android:layout_width="wrap_content"
69. android:layout_height="match_parent"
70. android:layout_weight="1"
71. android:text="饱和"/>
72. <Button
73. android:id="@+id/button6"
74. android:layout_width="wrap_content"
75. android:layout_height="match_parent"
76. android:layout_weight="1"
77. android:text="对比"/>
78. </LinearLayout>
79. </RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/container"    android:layout_width="match_parent"    android:layout_height="wrap_content"    tools:context="com.example.cangeimagetest.MainActivity"    tools:ignore="MergeRootFrame" >        <LinearLayout         android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="vertical" >        <Button        android:id="@+id/button1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="选择图片" />    <TextView        android:id="@+id/textView1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:visibility="invisible"        android:text="原图显示" />    <ImageView        android:id="@+id/imageView1"        android:layout_width="wrap_content"        android:layout_gravity="center_horizontal"        android:layout_height="wrap_content" />    <TextView        android:id="@+id/textView2"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:visibility="invisible"        android:text="变化后的图片" />    <ImageView        android:id="@+id/imageView2"        android:layout_gravity="center_horizontal"        android:layout_marginBottom="20dp"         android:layout_width="wrap_content"        android:layout_height="wrap_content" />    </LinearLayout>        <LinearLayout         android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="horizontal"    android:layout_alignParentBottom="true" >        <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="match_parent"        android:layout_weight="1"        android:text="缩小" />        <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="match_parent"        android:layout_weight="1"        android:text="放大" />        <Button        android:id="@+id/button4"        android:layout_width="wrap_content"        android:layout_height="match_parent"        android:layout_weight="1"        android:text="旋转" />        <Button        android:id="@+id/button5"        android:layout_width="wrap_content"        android:layout_height="match_parent"        android:layout_weight="1"        android:text="饱和" />        <Button        android:id="@+id/button6"        android:layout_width="wrap_content"        android:layout_height="match_parent"        android:layout_weight="1"        android:text="对比" />    </LinearLayout></RelativeLayout>

然后,在Mainctivity.java中public class MainActivity extends Activity函数添加代码如下：

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1. privateButtonselectBn;
2. privateImageViewimageShow;
3. privateImageViewimageCreate;
4. privateTextViewtextview1;
5. privateTextViewtextview2;
6. privateBitmapbmp;//原始图片
8. @Override
9. protectedvoidonCreate(BundlesavedInstanceState){
10. super.onCreate(savedInstanceState);
11. setContentView(R.layout.activity_main);
12. selectBn=(Button)findViewById(R.id.button1);
13. imageShow=(ImageView)findViewById(R.id.imageView1);
14. imageCreate=(ImageView)findViewById(R.id.imageView2);
15. textview1=(TextView)findViewById(R.id.textView1);
16. textview2=(TextView)findViewById(R.id.textView2);
18. //选择图片
19. selectBn.setOnClickListener(newOnClickListener(){
20. @Override
21. publicvoidonClick(Viewv){
22. Intentintent=newIntent(Intent.ACTION_PICK,
23. android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
24. startActivityForResult(intent,0);
25. }
26. });
27. if(savedInstanceState==null){
28. getFragmentManager().beginTransaction()
29. .add(R.id.container,newPlaceholderFragment())
30. .commit();
31. }
32. }
33. //显示两张图片
34. protectedvoidonActivityResult(intrequestCode,intresultCode,Intentdata){
35. super.onActivityResult(requestCode,resultCode,data);
36. if(resultCode==RESULT_OK){
37. ShowPhotoByImageView(data);//显示照片
38. CreatePhotoByImageView();//创建图片
39. }
40. }

private Button selectBn;private ImageView imageShow;private ImageView imageCreate;private TextView textview1;private TextView textview2;private Bitmap bmp; //原始图片@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    selectBn = (Button) findViewById(R.id.button1);    imageShow = (ImageView) findViewById(R.id.imageView1);    imageCreate = (ImageView) findViewById(R.id.imageView2);    textview1 = (TextView) findViewById(R.id.textView1);    textview2 = (TextView) findViewById(R.id.textView2);        //选择图片    selectBn.setOnClickListener(new OnClickListener() {    @Override    public void onClick(View v) {    Intent intent = new Intent(Intent.ACTION_PICK,     android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);    startActivityForResult(intent, 0 );    }    });    if (savedInstanceState == null) {        getFragmentManager().beginTransaction()                .add(R.id.container, new PlaceholderFragment())                .commit();    }}//显示两张图片protected void onActivityResult(int requestCode, int resultCode, Intent data) {  super.onActivityResult(requestCode, resultCode, data);if(resultCode==RESULT_OK) {ShowPhotoByImageView(data);     //显示照片CreatePhotoByImageView();          //创建图片}}

再调用自定义函数实现显示图片：

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1. //自定义函数显示打开的照片在ImageView1中
2. publicvoidShowPhotoByImageView(Intentdata){
3. UriimageFileUri=data.getData();
4. DisplayMetricsdm=newDisplayMetrics();
5. getWindowManager().getDefaultDisplay().getMetrics(dm);
6. intwidth=dm.widthPixels;//手机屏幕水平分辨率
7. intheight=dm.heightPixels;//手机屏幕垂直分辨率
8. Log.v("height",""+height);
9. Log.v("width",""+width);
10. try{
11. //Loaduptheimage'sdimensionsnottheimageitself
12. BitmapFactory.OptionsbmpFactoryOptions=newBitmapFactory.Options();
13. bmpFactoryOptions.inJustDecodeBounds=true;
14. bmp=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri),null,bmpFactoryOptions);
15. intheightRatio=(int)Math.ceil(bmpFactoryOptions.outHeight/(float)height);
16. intwidthRatio=(int)Math.ceil(bmpFactoryOptions.outWidth/(float)width);
17. Log.v("bmpheight",""+bmpFactoryOptions.outHeight);
18. Log.v("bmpheight",""+bmpFactoryOptions.outWidth);
19. if(heightRatio>1&&widthRatio>1){
20. if(heightRatio>widthRatio){
21. bmpFactoryOptions.inSampleSize=heightRatio*2;
22. }
23. else{
24. bmpFactoryOptions.inSampleSize=widthRatio*2;
25. }
26. }
27. //图像真正解码
28. bmpFactoryOptions.inJustDecodeBounds=false;
29. bmp=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri),null,bmpFactoryOptions);
30. imageShow.setImageBitmap(bmp);//将剪裁后照片显示出来
31. textview1.setVisibility(View.VISIBLE);
32. }catch(FileNotFoundExceptione){
33. e.printStackTrace();
34. }
35. }
36. //创建第二张图片并显示
37. publicvoidCreatePhotoByImageView(){
38. try{
39. BitmapcreateBmp=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
40. Canvascanvas=newCanvas(createBmp);//画布传入位图用于绘制
41. Paintpaint=newPaint();//画刷改变颜色对比度等属性
42. canvas.drawBitmap(bmp,0,0,paint);//错误:没有图片因为参数bmp写成createBmp
43. imageCreate.setImageBitmap(createBmp);
44. textview2.setVisibility(View.VISIBLE);
45. }catch(Exceptione){
46. e.printStackTrace();
47. }
48. }

//自定义函数 显示打开的照片在ImageView1中public void ShowPhotoByImageView(Intent data) {Uri imageFileUri = data.getData();DisplayMetrics dm = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(dm);int width = dm.widthPixels;    //手机屏幕水平分辨率int height = dm.heightPixels;  //手机屏幕垂直分辨率Log.v("height", ""+height );Log.v("width", ""+width);try {// Load up the image's dimensions not the image itselfBitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();bmpFactoryOptions.inJustDecodeBounds = true;bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactoryOptions);int heightRatio = (int)Math.ceil(bmpFactoryOptions.outHeight/(float)height);int widthRatio = (int)Math.ceil(bmpFactoryOptions.outWidth/(float)width);Log.v("bmpheight", ""+bmpFactoryOptions.outHeight);Log.v("bmpheight", ""+bmpFactoryOptions.outWidth);if(heightRatio>1&&widthRatio>1) {if(heightRatio>widthRatio) {bmpFactoryOptions.inSampleSize = heightRatio*2;}else {bmpFactoryOptions.inSampleSize = widthRatio*2;}} //图像真正解码       bmpFactoryOptions.inJustDecodeBounds = false;              bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactoryOptions);      imageShow.setImageBitmap(bmp); //将剪裁后照片显示出来      textview1.setVisibility(View.VISIBLE);} catch(FileNotFoundException e) {e.printStackTrace();}}//创建第二张图片并显示public void CreatePhotoByImageView() {try {    Bitmap createBmp = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());    Canvas canvas = new Canvas(createBmp); //画布 传入位图用于绘制    Paint paint = new Paint(); //画刷 改变颜色 对比度等属性    canvas.drawBitmap(bmp, 0, 0, paint);    //错误:没有图片 因为参数bmp写成createBmp    imageCreate.setImageBitmap(createBmp);    textview2.setVisibility(View.VISIBLE);} catch(Exception e) {e.printStackTrace();}}

显示的效果如下图所示,该图叫莱娜图(Lenna),是图像处理中经常使用的样例图.

二. Matrix操作

然后通过Matrix对图像进行处理操作,在onCreate函数中添加点击事件:

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1. //缩小图片
2. Buttonbutton2=(Button)findViewById(R.id.button2);
3. button2.setOnClickListener(newOnClickListener(){
4. @Override
5. publicvoidonClick(Viewv){
6. SmallPicture();
7. }
8. });
9. //放大图片
10. Buttonbutton3=(Button)findViewById(R.id.button3);
11. button3.setOnClickListener(newOnClickListener(){
12. @Override
13. publicvoidonClick(Viewv){
14. BigPicture();
15. }
16. });
17. //旋转图片
18. Buttonbutton4=(Button)findViewById(R.id.button4);
19. button4.setOnClickListener(newOnClickListener(){
20. @Override
21. publicvoidonClick(Viewv){
22. TurnPicture();
23. }
24. });
25. //图片饱和度改变
26. Buttonbutton5=(Button)findViewById(R.id.button5);
27. button5.setOnClickListener(newOnClickListener(){
28. @Override
29. publicvoidonClick(Viewv){
30. SaturationPicture();
31. }
32. });
33. //图片对比度改变
34. Buttonbutton6=(Button)findViewById(R.id.button6);
35. button6.setOnClickListener(newOnClickListener(){
36. @Override
37. publicvoidonClick(Viewv){
38. ContrastPicture();
39. }
40. });

//缩小图片Button button2=(Button)findViewById(R.id.button2);button2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {SmallPicture();}});//放大图片    Button button3=(Button)findViewById(R.id.button3);    button3.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {BigPicture();}});   //旋转图片Button button4=(Button)findViewById(R.id.button4);button4.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {TurnPicture();}});//图片饱和度改变Button button5=(Button)findViewById(R.id.button5);button5.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {SaturationPicture();}});//图片对比度改变Button button6=(Button)findViewById(R.id.button6);button6.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {ContrastPicture();}});

最后分别自定义函数各操作实现,代码如下：

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1. //缩小图片
2. privatevoidSmallPicture(){
3. Matrixmatrix=newMatrix();
4. //缩放区间0.5-1.0
5. if(smallbig>0.5f)
6. smallbig=smallbig-0.1f;
7. else
8. smallbig=0.5f;
9. //xy坐标同时缩放
10. matrix.setScale(smallbig,smallbig,bmp.getWidth()/2,bmp.getHeight()/2);
11. BitmapcreateBmp=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
12. Canvascanvas=newCanvas(createBmp);//画布传入位图用于绘制
13. Paintpaint=newPaint();//画刷改变颜色对比度等属性
14. canvas.drawBitmap(bmp,matrix,paint);
15. imageCreate.setBackgroundColor(Color.RED);
16. imageCreate.setImageBitmap(createBmp);
17. textview2.setVisibility(View.VISIBLE);
18. }
19. //放大图片
20. privatevoidBigPicture(){
21. Matrixmatrix=newMatrix();
22. //缩放区间0.5-1.0
23. if(smallbig<1.5f)
24. smallbig=smallbig+0.1f;
25. else
26. smallbig=1.5f;
27. //xy坐标同时缩放
28. matrix.setScale(smallbig,smallbig,bmp.getWidth()/2,bmp.getHeight()/2);
29. BitmapcreateBmp=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
30. Canvascanvas=newCanvas(createBmp);
31. Paintpaint=newPaint();
32. canvas.drawBitmap(bmp,matrix,paint);
33. imageCreate.setBackgroundColor(Color.RED);
34. imageCreate.setImageBitmap(createBmp);
35. textview2.setVisibility(View.VISIBLE);
36. }
37. //旋转图片
38. privatevoidTurnPicture(){
39. Matrixmatrix=newMatrix();
40. turnRotate=turnRotate+15;
41. //选择角度饶(0,0)点选择正数顺时针负数逆时针中心旋转
42. matrix.setRotate(turnRotate,bmp.getWidth()/2,bmp.getHeight()/2);
43. BitmapcreateBmp=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
44. Canvascanvas=newCanvas(createBmp);
45. Paintpaint=newPaint();
46. canvas.drawBitmap(bmp,matrix,paint);
47. imageCreate.setBackgroundColor(Color.RED);
48. imageCreate.setImageBitmap(createBmp);
49. textview2.setVisibility(View.VISIBLE);
50. }
51. //改变图像饱和度
52. privatevoidSaturationPicture(){
53. //设置饱和度0表示灰度图像大于1饱和度增加0-1饱和度减小
54. ColorMatrixcm=newColorMatrix();
55. cm.setSaturation(saturation);
56. Paintpaint=newPaint();
57. paint.setColorFilter(newColorMatrixColorFilter(cm));
58. //显示图片
59. Matrixmatrix=newMatrix();
60. BitmapcreateBmp=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
61. Canvascanvas=newCanvas(createBmp);
62. canvas.drawBitmap(bmp,matrix,paint);
63. imageCreate.setImageBitmap(createBmp);
64. textview2.setVisibility(View.VISIBLE);
65. saturation=saturation+0.1f;
66. if(saturation>=1.5f){
67. saturation=0f;
68. }
69. }
70. //设置图片对比度
71. privatevoidContrastPicture(){
72. ColorMatrixcm=newColorMatrix();
73. floatbrightness=-25;//亮度
74. floatcontrast=2;//对比度
75. cm.set(newfloat[]{
76. contrast,0,0,0,brightness,
77. 0,contrast,0,0,brightness,
78. 0,0,contrast,0,brightness,
79. 0,0,0,contrast,0
80. });
81. Paintpaint=newPaint();
82. paint.setColorFilter(newColorMatrixColorFilter(cm));
83. //显示图片
84. Matrixmatrix=newMatrix();
85. BitmapcreateBmp=Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
86. Canvascanvas=newCanvas(createBmp);
87. canvas.drawBitmap(bmp,matrix,paint);
88. imageCreate.setImageBitmap(createBmp);
89. textview2.setVisibility(View.VISIBLE);
90. }

//缩小图片private void SmallPicture() {Matrix matrix = new Matrix();//缩放区间 0.5-1.0if(smallbig>0.5f)smallbig=smallbig-0.1f;elsesmallbig=0.5f;//x y坐标同时缩放matrix.setScale(smallbig,smallbig,bmp.getWidth()/2,bmp.getHeight()/2); Bitmap createBmp = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());Canvas canvas = new Canvas(createBmp); //画布 传入位图用于绘制Paint paint = new Paint(); //画刷 改变颜色 对比度等属性    canvas.drawBitmap(bmp, matrix, paint);    imageCreate.setBackgroundColor(Color.RED);    imageCreate.setImageBitmap(createBmp);    textview2.setVisibility(View.VISIBLE);    }  //放大图片private void BigPicture() {Matrix matrix = new Matrix();//缩放区间 0.5-1.0if(smallbig<1.5f)smallbig=smallbig+0.1f;elsesmallbig=1.5f;//x y坐标同时缩放matrix.setScale(smallbig,smallbig,bmp.getWidth()/2,bmp.getHeight()/2); Bitmap createBmp = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());Canvas canvas = new Canvas(createBmp); Paint paint = new Paint(); canvas.drawBitmap(bmp, matrix, paint);imageCreate.setBackgroundColor(Color.RED);imageCreate.setImageBitmap(createBmp);textview2.setVisibility(View.VISIBLE);}//旋转图片private void TurnPicture() {Matrix matrix = new Matrix();turnRotate=turnRotate+15;//选择角度 饶(0,0)点选择 正数顺时针 负数逆时针 中心旋转matrix.setRotate(turnRotate,bmp.getWidth()/2,bmp.getHeight()/2); Bitmap createBmp = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());Canvas canvas = new Canvas(createBmp); Paint paint = new Paint(); canvas.drawBitmap(bmp, matrix, paint);imageCreate.setBackgroundColor(Color.RED);imageCreate.setImageBitmap(createBmp);textview2.setVisibility(View.VISIBLE);}//改变图像饱和度private void SaturationPicture() {//设置饱和度 0表示灰度图像 大于1饱和度增加 0-1饱和度减小ColorMatrix cm = new ColorMatrix();cm.setSaturation(saturation);Paint paint = new Paint(); paint.setColorFilter(new ColorMatrixColorFilter(cm));//显示图片Matrix matrix = new Matrix();Bitmap createBmp = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());Canvas canvas = new Canvas(createBmp); canvas.drawBitmap(bmp, matrix, paint);imageCreate.setImageBitmap(createBmp);textview2.setVisibility(View.VISIBLE);saturation=saturation+0.1f;if(saturation>=1.5f) {saturation=0f;}}//设置图片对比度private void ContrastPicture() {ColorMatrix cm = new ColorMatrix();float brightness = -25;  //亮度float contrast = 2;        //对比度cm.set(new float[] {contrast, 0, 0, 0, brightness,0, contrast, 0, 0, brightness,0, 0, contrast, 0, brightness,0, 0, 0, contrast, 0});Paint paint = new Paint(); paint.setColorFilter(new ColorMatrixColorFilter(cm));//显示图片Matrix matrix = new Matrix();Bitmap createBmp = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());Canvas canvas = new Canvas(createBmp); canvas.drawBitmap(bmp, matrix, paint);imageCreate.setImageBitmap(createBmp);textview2.setVisibility(View.VISIBLE);}

同时自定义变量如下：

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1. //图片变换参数
2. privatefloatsmallbig=1.0f;//缩放比例
3. privateintturnRotate=0;//旋转度数
4. privatefloatsaturation=0f;//饱和度

//图片变换参数private float smallbig=1.0f;   //缩放比例private int turnRotate=0;       //旋转度数private float saturation=0f;    //饱和度

它的运行结果如下图所示：



需要指出的是：该项目仅仅讲述处理的过程,并没有考虑很多因素,如:有的图像显示可能超出屏幕,没有载入图片点击处理按钮报错,横竖屏切换导致不显示图片,最下面按钮可能被遮挡,图像放大画布没有变,因为为认为显示一张改变后的图片效果更好,而该工程仅仅是对比.图像缩放移动触屏变换更好,下一篇讲述.
XML布局推荐：http://www.apkbus.com/forum.php?mod=viewthread&tid=44949
解决画布跟着图片放大：http://www.eoeandroid.com/thread-3162-1-1.html

三. Matrix处理的原理

Android中可以通过Matrix和ColorMatrix对图像进行处理.
1.Matrix
图像空间变换,包括旋转、剪裁、缩放或移动.Matrix类中每个数字都将应用于图像上每个点的3个坐标x\y\z之一.
如下代码通过setValues设置值.(1,0,0)表示x坐标转换x=1x+0y+0z,同样y=0x+1y+0z,z=0x+0y+1z.该矩阵不做任何变换.如果第一行改为(.5f,0,0),那么图像在x轴上将图像压缩50%.移动见setTranslate()函数.

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1. Matrixmatrix=newMatrix();
2. matrix.setValues(newfloat[]{
3. 1,0,0,
4. 0,1,0,
5. 0,0,1
6. });

Matrix matrix = new Matrix();matrix.setValues(new float[] {        1, 0, 0,        0, 1, 0,        0, 0, 1});

2.ColorMatrix
在Canvas(画布)对象上绘制时既可使用Matrix方法,也可使用ColorMatrix来改变在Canvas对象上绘制的Paint(画刷)对象.对图像的像素处理时,每个像素由RGBA值组成(Red Green Blue Alpha).具体方法推荐博文:http://www.cnblogs.com/leon19870907/articles/1978065.html
最后希望该文章对大家有所帮助,尤其是Android初学者.该文章是讲述Android使用Matrix处理图片的基础文章,如果有不足或错误地方,请见谅~参考资料《Android多媒体开发高级编程 著：Shawn Van Every》
下载地址:http://download.csdn.net/detail/eastmount/8082043
(By:Eastmount 2014-10-26 夜2点 http://blog.csdn.net/eastmount)

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