Android图像处理技巧实例

导语

书上讲的很细，还讲了一些原理，原理需要一些线性代数的知识，线代都忘光了，这里都是实例，想看理论知识戳我。

主要内容

通过SeekBar调节色调、饱和度、亮度

模拟4x5的颜色矩阵

底片效果、老照片效果、浮雕效果

飘动的旗子

刮刮卡效果

倒影图片效果

正弦曲线

绘图板

具体内容

通过SeekBar调节色调、饱和度、亮度

布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<ImageView
android:id="@+id/imageview"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_centerHorizontal="true"
android:layout_marginBottom="24dp"
android:layout_marginTop="24dp" />

<SeekBar
android:id="@+id/seekbarHue"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/imageview" />

<SeekBar
android:id="@+id/seekbarSaturation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/seekbarHue" />

<SeekBar
android:id="@+id/seekbatLum"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/seekbarSaturation" />

</RelativeLayout>

Activity：

public class PrimaryColor extends Activity implements SeekBar.OnSeekBarChangeListener {

private static int MAX_VALUE = 255;
private static int MID_VALUE = 127;
private ImageView mImageView;
private SeekBar mSeekbarhue, mSeekbarSaturation, mSeekbarLum;
private float mHue, mStauration, mLum;
private Bitmap bitmap;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.primary_color);
bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.test3);
mImageView = (ImageView) findViewById(R.id.imageview);
mSeekbarhue = (SeekBar) findViewById(R.id.seekbarHue);
mSeekbarSaturation = (SeekBar) findViewById(R.id.seekbarSaturation);
mSeekbarLum = (SeekBar) findViewById(R.id.seekbatLum);
mSeekbarhue.setOnSeekBarChangeListener(this);
mSeekbarSaturation.setOnSeekBarChangeListener(this);
mSeekbarLum.setOnSeekBarChangeListener(this);
mSeekbarhue.setMax(MAX_VALUE);
mSeekbarSaturation.setMax(MAX_VALUE);
mSeekbarLum.setMax(MAX_VALUE);
mSeekbarhue.setProgress(MID_VALUE);
mSeekbarSaturation.setProgress(MID_VALUE);
mSeekbarLum.setProgress(MID_VALUE);
mImageView.setImageBitmap(bitmap);
}

@Override
public void onProgressChanged(SeekBar seekBar,
int progress, boolean fromUser) {
switch (seekBar.getId()) {
case R.id.seekbarHue:
mHue = (progress - MID_VALUE) * 1.0F / MID_VALUE * 180;
break;
case R.id.seekbarSaturation:
mStauration = progress * 1.0F / MID_VALUE;
break;
case R.id.seekbatLum:
mLum = progress * 1.0F / MID_VALUE;
break;
}
mImageView.setImageBitmap(ImageHelper.handleImageEffect(
bitmap, mHue, mStauration, mLum));
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
}

ImageHelper：

public class ImageHelper {

public static Bitmap handleImageEffect(Bitmap bm,
float hue,
float saturation,
float lum) {
Bitmap bmp = Bitmap.createBitmap(
bm.getWidth(), bm.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bmp);
Paint paint = new Paint();

ColorMatrix hueMatrix = new ColorMatrix();
hueMatrix.setRotate(0, hue);
hueMatrix.setRotate(1, hue);
hueMatrix.setRotate(2, hue);

ColorMatrix saturationMatrix = new ColorMatrix();
saturationMatrix.setSaturation(saturation);

ColorMatrix lumMatrix = new ColorMatrix();
lumMatrix.setScale(lum, lum, lum, 1);

ColorMatrix imageMatrix = new ColorMatrix();
imageMatrix.postConcat(hueMatrix);
imageMatrix.postConcat(saturationMatrix);
imageMatrix.postConcat(lumMatrix);

paint.setColorFilter(new ColorMatrixColorFilter(imageMatrix));
canvas.drawBitmap(bm, 0, 0, paint);
return bmp;
}

}

效果图：

模拟4x5的颜色矩阵

布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<ImageView
android:id="@+id/imageview"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="2" />

<GridLayout
android:id="@+id/group"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="3"
android:columnCount="5"
android:rowCount="4">

</GridLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:onClick="btnChange"
android:text="Change" />

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:onClick="btnReset"
android:text="Reset" />
</LinearLayout>

</LinearLayout>

Activity：

public class ColorMatrix extends Activity {

private ImageView mImageView;
private GridLayout mGroup;
private Bitmap bitmap;
private int mEtWidth, mEtHeight;
private EditText[] mEts = new EditText[20];
private float[] mColorMatrix = new float[20];

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.color_matrix);
bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.test1);
mImageView = (ImageView) findViewById(R.id.imageview);
mGroup = (GridLayout) findViewById(R.id.group);
mImageView.setImageBitmap(bitmap);

mGroup.post(new Runnable() {
@Override
public void run() {
// 获取宽高信息
mEtWidth = mGroup.getWidth() / 5;
mEtHeight = mGroup.getHeight() / 4;
addEts();
initMatrix();
}
});
}

// 获取矩阵值
private void getMatrix() {
for (int i = 0; i < 20; i++) {
mColorMatrix[i] = Float.valueOf(
mEts[i].getText().toString());
}
}

// 将矩阵值设置到图像
private void setImageMatrix() {
Bitmap bmp = Bitmap.createBitmap(
bitmap.getWidth(),
bitmap.getHeight(),
Bitmap.Config.ARGB_8888);
android.graphics.ColorMatrix colorMatrix =
new android.graphics.ColorMatrix();
colorMatrix.set(mColorMatrix);

Canvas canvas = new Canvas(bmp);
Paint paint = new Paint();
paint.setColorFilter(new ColorMatrixColorFilter(colorMatrix));
canvas.drawBitmap(bitmap, 0, 0, paint);
mImageView.setImageBitmap(bmp);
}

// 作用矩阵效果
public void btnChange(View view) {
getMatrix();
setImageMatrix();
}

// 重置矩阵效果
public void btnReset(View view) {
initMatrix();
getMatrix();
setImageMatrix();
}

// 添加EditText
private void addEts() {
for (int i = 0; i < 20; i++) {
EditText editText = new EditText(ColorMatrix.this);
mEts[i] = editText;
mGroup.addView(editText, mEtWidth, mEtHeight);
}
}

// 初始化颜色矩阵为初始状态
private void initMatrix() {
for (int i = 0; i < 20; i++) {
if (i % 6 == 0) {
mEts[i].setText(String.valueOf(1));
} else {
mEts[i].setText(String.valueOf(0));
}
}
}
}

关键点：将一个颜色矩阵传入画笔，然后画出原始的图在新建的图上面。

paint.setColorFilter(new ColorMatrixColorFilter(colorMatrix));

效果图：

底片效果、老照片效果、浮雕效果

布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">

<ImageView
android:id="@+id/imageview1"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />

<ImageView
android:id="@+id/imageview2"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">

<ImageView
android:id="@+id/imageview3"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />

<ImageView
android:id="@+id/imageview4"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1" />
</LinearLayout>

</LinearLayout>

Activity：

public class PixelsEffect extends Activity {

private ImageView imageView1, imageView2, imageView3, imageView4;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.pixels_effect);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.test2);
imageView1 = (ImageView) findViewById(R.id.imageview1);
imageView2 = (ImageView) findViewById(R.id.imageview2);
imageView3 = (ImageView) findViewById(R.id.imageview3);
imageView4 = (ImageView) findViewById(R.id.imageview4);

imageView1.setImageBitmap(bitmap);
imageView2.setImageBitmap(ImageHelper.handleImageNegative(bitmap));
imageView3.setImageBitmap(ImageHelper.handleImagePixelsOldPhoto(bitmap));
imageView4.setImageBitmap(ImageHelper.handleImagePixelsRelief(bitmap));
}
}

工具类：

public class ImageHelper {

public static Bitmap handleImageNegative(Bitmap bm) {
int width = bm.getWidth();
int height = bm.getHeight();
int color;
int r, g, b, a;

Bitmap bmp = Bitmap.createBitmap(width, height
, Bitmap.Config.ARGB_8888);

int[] oldPx = new int[width * height];
int[] newPx = new int[width * height];
bm.getPixels(oldPx, 0, width, 0, 0, width, height);

for (int i = 0; i < width * height; i++) {
color = oldPx[i];
r = Color.red(color);
g = Color.green(color);
b = Color.blue(color);
a = Color.alpha(color);

r = 255 - r;
g = 255 - g;
b = 255 - b;

if (r > 255) {
r = 255;
} else if (r < 0) {
r = 0;
}
if (g > 255) {
g = 255;
} else if (g < 0) {
g = 0;
}
if (b > 255) {
b = 255;
} else if (b < 0) {
b = 0;
}
newPx[i] = Color.argb(a, r, g, b);
}
bmp.setPixels(newPx, 0, width, 0, 0, width, height);
return bmp;
}

public static Bitmap handleImagePixelsOldPhoto(Bitmap bm) {
Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(),
Bitmap.Config.ARGB_8888);
int width = bm.getWidth();
int height = bm.getHeight();
int color = 0;
int r, g, b, a, r1, g1, b1;

int[] oldPx = new int[width * height];
int[] newPx = new int[width * height];

bm.getPixels(oldPx, 0, bm.getWidth(), 0, 0, width, height);
for (int i = 0; i < width * height; i++) {
color = oldPx[i];
a = Color.alpha(color);
r = Color.red(color);
g = Color.green(color);
b = Color.blue(color);

r1 = (int) (0.393 * r + 0.769 * g + 0.189 * b);
g1 = (int) (0.349 * r + 0.686 * g + 0.168 * b);
b1 = (int) (0.272 * r + 0.534 * g + 0.131 * b);

if (r1 > 255) {
r1 = 255;
}
if (g1 > 255) {
g1 = 255;
}
if (b1 > 255) {
b1 = 255;
}

newPx[i] = Color.argb(a, r1, g1, b1);
}
bmp.setPixels(newPx, 0, width, 0, 0, width, height);
return bmp;
}

public static Bitmap handleImagePixelsRelief(Bitmap bm) {
Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(),
Bitmap.Config.ARGB_8888);
int width = bm.getWidth();
int height = bm.getHeight();
int color = 0, colorBefore = 0;
int a, r, g, b;
int r1, g1, b1;

int[] oldPx = new int[width * height];
int[] newPx = new int[width * height];

bm.getPixels(oldPx, 0, bm.getWidth(), 0, 0, width, height);
for (int i = 1; i < width * height; i++) {
colorBefore = oldPx[i - 1];
a = Color.alpha(colorBefore);
r = Color.red(colorBefore);
g = Color.green(colorBefore);
b = Color.blue(colorBefore);

color = oldPx[i];
r1 = Color.red(color);
g1 = Color.green(color);
b1 = Color.blue(color);

r = (r - r1 + 127);
g = (g - g1 + 127);
b = (b - b1 + 127);
if (r > 255) {
r = 255;
}
if (g > 255) {
g = 255;
}
if (b > 255) {
b = 255;
}
newPx[i] = Color.argb(a, r, g, b);
}
bmp.setPixels(newPx, 0, width, 0, 0, width, height);
return bmp;
}
}

效果图：

飘动的旗子

FlagBitmapMeshView：

public class FlagBitmapMeshView extends View {

private final int WIDTH = 200;
private final int HEIGHT = 200;
private int COUNT = (WIDTH + 1) * (HEIGHT + 1);
private float[] verts = new float[COUNT * 2];
private float[] orig = new float[COUNT * 2];
private Bitmap bitmap;
private float A;
private float k = 1;

public FlagBitmapMeshView(Context context) {
super(context);
initView(context);
}

public FlagBitmapMeshView(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context);
}

public FlagBitmapMeshView(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
initView(context);
}

private void initView(Context context) {
setFocusable(true);
bitmap = BitmapFactory.decodeResource(context.getResources(),
R.drawable.test);
float bitmapWidth = bitmap.getWidth();
float bitmapHeight = bitmap.getHeight();
int index = 0;
for (int y = 0; y <= HEIGHT; y++) {
float fy = bitmapHeight * y / HEIGHT;
for (int x = 0; x <= WIDTH; x++) {
float fx = bitmapWidth * x / WIDTH;
orig[index * 2 + 0] = verts[index * 2 + 0] = fx;
orig[index * 2 + 1] = verts[index * 2 + 1] = fy + 100;
index += 1;
}
}
A = 50;
}

@Override
protected void onDraw(Canvas canvas) {
flagWave();
k += 0.1F;
canvas.drawBitmapMesh(bitmap, WIDTH, HEIGHT,
verts, 0, null, 0, null);
invalidate();
}

private void flagWave() {
for (int j = 0; j <= HEIGHT; j++) {
for (int i = 0; i <= WIDTH; i++) {
verts[(j * (WIDTH + 1) + i) * 2 + 0] += 0;
float offsetY =
(float) Math.sin((float) i / WIDTH * 2 * Math.PI +
Math.PI * k);
verts[(j * (WIDTH + 1) + i) * 2 + 1] =
orig[(j * WIDTH + i) * 2 + 1] + offsetY * A;
}
}
}
}

效果图：

刮刮卡效果

XfermodeView：

public class XfermodeView extends View {

private Bitmap mBgBitmap, mFgBitmap;
private Paint mPaint;
private Canvas mCanvas;
private Path mPath;

public XfermodeView(Context context) {
super(context);
init();
}

public XfermodeView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}

public XfermodeView(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}

private void init() {
mPaint = new Paint();
mPaint.setAlpha(0);
mPaint.setXfermode(
new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeWidth(50);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPath = new Path();
mBgBitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.test);
mFgBitmap = Bitmap.createBitmap(mBgBitmap.getWidth(),
mBgBitmap.getHeight(), Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mFgBitmap);
mCanvas.drawColor(Color.GRAY);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPath.reset();
mPath.moveTo(event.getX(), event.getY());
break;
case MotionEvent.ACTION_MOVE:
mPath.lineTo(event.getX(), event.getY());
break;
}
mCanvas.drawPath(mPath, mPaint);
invalidate();
return true;
}

@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBgBitmap, 0, 0, null);
canvas.drawBitmap(mFgBitmap, 0, 0, null);
}
}

效果图：

倒影图片效果

ReflectView：

public class ReflectView extends View {
private Bitmap mSrcBitmap, mRefBitmap;
private Paint mPaint;
private PorterDuffXfermode mXfermode;

public ReflectView(Context context) {
super(context);
initRes(context);
}

public ReflectView(Context context, AttributeSet attrs) {
super(context, attrs);
initRes(context);
}

public ReflectView(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
initRes(context);
}

private void initRes(Context context) {
mSrcBitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.test);
Matrix matrix = new Matrix();
matrix.setScale(1F, -1F);
mRefBitmap = Bitmap.createBitmap(mSrcBitmap, 0, 0,
mSrcBitmap.getWidth(), mSrcBitmap.getHeight(), matrix, true);

mPaint = new Paint();
mPaint.setShader(new LinearGradient(0, mSrcBitmap.getHeight(), 0,
mSrcBitmap.getHeight() + mSrcBitmap.getHeight() / 4,
0XDD000000, 0X10000000, Shader.TileMode.CLAMP));
mXfermode = new PorterDuffXfermode(PorterDuff.Mode.DST_IN);
}

@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.BLACK);
canvas.drawBitmap(mSrcBitmap, 0, 0, null);
canvas.drawBitmap(mRefBitmap, 0, mSrcBitmap.getHeight(), null);
mPaint.setXfermode(mXfermode);
// 绘制渐变效果矩形
canvas.drawRect(0, mSrcBitmap.getHeight(),
mRefBitmap.getWidth(), mSrcBitmap.getHeight() * 2, mPaint);
mPaint.setXfermode(null);
}
}

效果图：

正弦曲线

SinView：

public class SinView extends SurfaceView
implements SurfaceHolder.Callback, Runnable {

private SurfaceHolder mHolder;
private Canvas mCanvas;
private boolean mIsDrawing;
private int x = 0;
private int y = 0;
private Path mPath;
private Paint mPaint;

public SinView(Context context) {
super(context);
initView();
}

public SinView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}

public SinView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initView();
}

private void initView() {
mHolder = getHolder();
mHolder.addCallback(this);
setFocusable(true);
setFocusableInTouchMode(true);
this.setKeepScreenOn(true);
mPath = new Path();
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setColor(Color.RED);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(10);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeJoin(Paint.Join.ROUND);
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
mIsDrawing = true;
mPath.moveTo(0, 400);
new Thread(this).start();
}

@Override
public void surfaceChanged(SurfaceHolder holder,
int format, int width, int height) {
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mIsDrawing = false;
}

@Override
public void run() {
while (mIsDrawing) {
draw();
x += 1;
y = (int) (100*Math.sin(x * 2 * Math.PI / 180) + 400);
mPath.lineTo(x, y);
}
}

private void draw() {
try {
mCanvas = mHolder.lockCanvas();
// SurfaceView背景
mCanvas.drawColor(Color.WHITE);
mCanvas.drawPath(mPath, mPaint);
} catch (Exception e) {
} finally {
if (mCanvas != null)
mHolder.unlockCanvasAndPost(mCanvas);
}
}
}

效果图：

绘图板

SimpleDraw：

public class SimpleDraw extends SurfaceView
implements SurfaceHolder.Callback, Runnable {

private SurfaceHolder mHolder;
private Canvas mCanvas;
private boolean mIsDrawing;
private Path mPath;
private Paint mPaint;

public SimpleDraw(Context context) {
super(context);
initView();
}

public SimpleDraw(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}

public SimpleDraw(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
initView();
}

private void initView() {
mHolder = getHolder();
mHolder.addCallback(this);
setFocusable(true);
setFocusableInTouchMode(true);
this.setKeepScreenOn(true);
mPath = new Path();
mPaint = new Paint();
mPaint.setColor(Color.RED);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(20);
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
mIsDrawing = true;
new Thread(this).start();
}

@Override
public void surfaceChanged(SurfaceHolder holder,
int format, int width, int height) {
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mIsDrawing = false;
}

@Override
public void run() {
long start = System.currentTimeMillis();
while (mIsDrawing) {
draw();
}
long end = System.currentTimeMillis();
// 50 - 100
if (end - start < 100) {
try {
Thread.sleep(100 - (end - start));
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

private void draw() {
try {
mCanvas = mHolder.lockCanvas();
mCanvas.drawColor(Color.WHITE);
mCanvas.drawPath(mPath, mPaint);
} catch (Exception e) {
} finally {
if (mCanvas != null)
mHolder.unlockCanvasAndPost(mCanvas);
}
}

@Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int) event.getX();
int y = (int) event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPath.moveTo(x, y);
break;
case MotionEvent.ACTION_MOVE:
mPath.lineTo(x, y);
break;
case MotionEvent.ACTION_UP:
break;
}
return true;
}
}

效果图：

总结

理解上面的案例。

进入我的CSDN戳这里（我的博客导航）