Android Bitmap颜色、亮度、饱和度等变化

颜色矩阵 ColorMatrix cm = new ColorMatrix();
paint.setColorFilter(new ColorMatrixColorFilter(cm));
1 0 0 0 0
0 1 0 0 0
0 0 1 0 0
0 0 0 1 0
New Red Value = 1*128 + 0*128 + 0*128 + 0*0 + 0
New Blue Value = 0*128 + 1*128 + 0*128 + 0*0 + 0
New Green Value = 0*128 + 0*128 + 1*128 + 0*0 + 0
New Alpha Value = 0*128 + 0*128 + 0*128 + 1*0 + 0
ColorMatrix cm = new ColorMatrix();
cm.set(new float[] {
2, 0, 0, 0, 0,
0, 1, 0, 0, 0,
0, 0, 1, 0, 0,
0, 0, 0, 1, 0
});
paint.setColorFilter(new ColorMatrixColorFilter(cm));

<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"    tools:context=".MainActivity" >    <Button        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="click"        android:text="拷贝一个位图" />    <ImageView        android:id="@+id/iv1"        android:layout_width="wrap_content"        android:layout_height="wrap_content" />    <ImageView        android:id="@+id/iv2"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></LinearLayout>

public class MainActivity extends Activity {    private ImageView iv1,iv2;    private Bitmap alterBitmap;    private Bitmap srcBmp;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        iv1 = (ImageView) findViewById(R.id.iv1);        iv2 = (ImageView) findViewById(R.id.iv2);        //给第一个imageview默认设置一个位图        srcBmp = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);        iv1.setImageBitmap(srcBmp);        //创建原图的一个副本。 可修改  创建的是一个空白的图形。        alterBitmap = Bitmap.createBitmap(srcBmp.getWidth()*2, srcBmp.getHeight()*2,srcBmp.getConfig());    }    /**     * 创建原图 bm的一个拷贝。副本     * @param view     */    public void click(View view){        //1.准备一个画板  在上面放上准备好的 空白的位图        Canvas canvas = new Canvas(alterBitmap);        //2.准备一个画笔        Paint paint = new Paint();        paint.setColor(Color.BLACK);        //3.画画        Matrix m = new Matrix();        ColorMatrix cm = new ColorMatrix();        cm.set(new float[] {        0.5f, 0, 0, 0, 0,        0, 0.8f, 0, 0, 0,        0, 0, 0.6f, 0, 0,        0, 0, 0, 1, 0        });        paint.setColorFilter(new ColorMatrixColorFilter(cm));        canvas.drawBitmap(srcBmp, m, paint);        iv2.setImageBitmap(alterBitmap);//把原图的副本设置到界面上。    }}

获取Exif图片信息

//从文件获取exif信息ExifInterface ei = new ExifInterface(imageFilePath);String imageDescription = ei.getAttribute("ImageDescription");if (imageDescription != null){Log.v("EXIF", imageDescription);}//把exif信息写到文件:ExifInterface ei = new ExifInterface(imageFilePath);ei.setAttribute("ImageDescription","Something New");

从gallery获取一个图片

Intent intent = new Intent(Intent.ACTION_PICK);intent.setType(“image/*”);intent.getData() 获取image的uriBitmap bmp = BitmapFactory.decodeStream(getContentResolver().��openInputStream(imageFileUri), null, bmpFactoryOptions);

变换图像的亮度

ColorMatrix cm = new ColorMatrix();float contrast = 2;cm.set(new float[] {contrast, 0, 0, 0, 0,0, contrast, 0, 0, 0,0, 0, contrast, 0, 0,0, 0, 0, 1, 0 });paint.setColorFilter(new ColorMatrixColorFilter(cm));

更改图片饱和度

ColorMatrix cm = new ColorMatrix();cm.setSaturation(.5f);paint.setColorFilter(new ColorMatrixColorFilter(cm));

图片合成

Bitmap drawingBitmap = Bitmap.createBitmap(bmp1.getWidth(),��bmp1.getHeight(), bmp1.getConfig());canvas = new Canvas(drawingBitmap);paint = new Paint();canvas.drawBitmap(bmp1, 0, 0, paint);paint.setXfermode(new PorterDuffXfermode(android.graphics.��PorterDuff.Mode.MULTIPLY));canvas.drawBitmap(bmp2, 0, 0, paint);

按指定path上绘制文字

Paint paint = new Paint();paint.setColor(Color.GREEN);paint.setTextSize(20);paint.setTypeface(Typeface.DEFAULT);Path p = new Path();p.moveTo(20, 20);p.lineTo(100, 150);p.lineTo(200, 220);canvas.drawTextOnPath("Hello this is text on a path", p, 0, 0, paint);

参考：
Android图片处理