我是 OpenCV4Android 和 Android NDK 的新手
努力实现
相对于图像上的触摸点拉伸图像。（将头发放在脸上并使用触摸事件相应地拉伸它，例如“虚拟化妆应用程序”)
问题：使用 Java 时
通过从位图获取矩阵并在触摸事件上重新计算它们，在触摸事件上实现了扭曲功能。但是图像会扭曲，整个矩阵会颠倒。
如何使用 OpenCV4Android 来实现这样的目标？
对这些的任何启发都会非常有帮助。
经过大量的图像处理库后，每个库都有扭曲和变形效果，但没有一个对触摸点有影响。正如他们中的许多人建议的那样，您可以使用 OpenCV4Android 或 OpenGL 来实现此类目标，但我不喜欢其中任何一个。
所以最终在C中用NDK实现了Warpping效果。
以下是应用于触摸点上的位图像素的算法。
#include <stdio.h>
#include <stdlib.h>
#include <jni.h>
#include <math.h>
#include <malloc.h>
#include <android/log.h>
#define LOG_TAG "System.out"
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
int *colorRed;
int *colorGreen;
int *colorBlue;
int *colorsP; //ÏñËØÖµ
int *colorAlpha;
int _width, _height;
jintArray imagecolors;
//²éÕÒ±í
static long SinXDivX_Table_8[(2 << 8) + 1];
double MySin(double x) {
double absx;
absx = x;
if (x < 0)
absx = -x;
WarpView 对触摸点产生扭曲效果：
public class WarpView extends View {
static {
System.loadLibrary("Hello");
}
public native int[] warpPhotoFromC(int[] image, int height, int width,
double max_dist, double orig_x, double orig_y, double cur_x,
double cur_y);
private static String TAG = WarpView.class.getSimpleName();
private Bitmap mBmp;
private int[] image;
private int first = 0;
private int[] colorR;
private int[] colorG;
private int[] colorB;
private Bitmap newBmp;
private boolean fg = true;
private Context context;
private static final int DEFAULT_PAINT_FLAGS = Paint.FILTER_BITMAP_FLAG
| Paint.DITHER_FLAG;
static Paint mPaint = new Paint(DEFAULT_PAINT_FLAGS);
public static int HWPPQ = 110;
public static int MMQFJ = 120;
private int MODE = MMQFJ;
// SA VIKALP
// public ArrayList<WarpViewUndo> mArrayListWarpViewUndo;
static GestureDetector mGestures;
static ScaleGestureDetector mScaleGesture;
private Matrix mMatrix = new Matrix();
private Matrix mInverse = new Matrix();
private float lastFocusX;
private float lastFocusY;
private boolean mIsMove = false;
// EA VIKALP
public WarpView(Context context) {
super(context);
}
public WarpView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
dest = new RectF(0, 0, 0, 0);
// SA VIKALP
// mArrayListWarpViewUndo = new ArrayList<WarpViewUndo>();
mScaleGesture = new ScaleGestureDetector(getContext(),
new ScaleListener());
mGestures = new GestureDetector(getContext(), new GestureListener());
mMatrix.setTranslate(5, 5);
mMatrix.invert(mInverse);
// EA VIKALP
}
@Override
protected void onDraw(Canvas canvas) {
// super.onDraw(canvas);
if (fg) {
int viewWidht = getWidth();
int viewHeight = getHeight();
float scale1 = (float) width / (float) viewWidht;
float scale2 = (float) height / (float) viewHeight;
scale = scale1 > scale2 ? scale1 : scale2;
int xoffset = (viewWidht - (int) (width / scale)) / 2;
int yoffset = (viewHeight - (int) (height / scale)) / 2;
dest.set(xoffset, yoffset, (int) (width / scale) + xoffset,
(int) (height / scale) + yoffset);// = new RectF(xoffset,
// yoffset, (int)
// (width/scale)+xoffset,
// (int)
// (height/scale)+yoffset);
// SA VIKALP
canvas.drawColor(0x000000);
canvas.concat(mMatrix);
// canvas.drawColor(Color.TRANSPARENT);
// canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
// EA VIKALP
canvas.drawBitmap(mBmp, null, dest, mPaint);
} else {
// SA VIKALP
canvas.drawColor(0x000000);
canvas.concat(mMatrix);
// canvas.drawColor(Color.TRANSPARENT);
// canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
// EA VIKALP
canvas.drawBitmap(newBmp, null, dest, mPaint);
}
}
private double orig_x, orig_y;
private double mou_dx, mou_dy;
private double max_dist, max_dist_sq;
private int width;
private int height;
private int count = 0;
private double mou_dx_norm;
private double mou_dy_norm;
private float scale;
private RectF dest;
private double move_x, move_y;
private int dist = (int) getResources().getDimension(R.dimen.max_dist);
private int line_height = (int) getResources().getDimension(
R.dimen.warp_line);
@Override
public boolean onTouchEvent(MotionEvent event) {
// SA VIKALP
mScaleGesture.onTouchEvent(event);
mGestures.onTouchEvent(event);
// EA VIKALP
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
orig_x = event.getX();
orig_y = event.getY();
orig_x = (orig_x - dest.left) * scale;
orig_y = (orig_y - dest.top) * scale;
break;
case MotionEvent.ACTION_MOVE:
if (!mIsMove) { // SA VIKALP ADDED LINE
max_dist = dist * scale;// Math.hypot(mou_dx, mou_dy);
if (event.getAction() != 1) {
// int m = event.getHistorySize();
move_x = event.getX();
move_y = event.getY();
move_x = (move_x - dest.left) * scale;
move_y = (move_y - dest.top) * scale;
// if(m > 0){
// int i2 = m + -1;
// orig_x = (event.getHistoricalX(i2) - dest.left)*scale;
// orig_y = (event.getHistoricalY(i2) - dest.top)*scale;
// }
if (move_x >= 0 && move_y >= 0) {
warpPhotoFromC(image, height, width, max_dist, orig_x,
orig_y, move_x, move_y);
first++;
newBmp.setPixels(image, 0, width, 0, 0, width, height);
fg = false;
}
}
orig_x = move_x;
orig_y = move_y;
}
break;
case MotionEvent.ACTION_UP:
break;
}
invalidate();
return true;
}
// SA VIKALP
// public void applyWarpUndo(Bitmap bmp) {
// setWarpBitmap(bmp);
// Log.i(TAG, "Size : "
// + mArrayListWarpViewUndo.size()
// + " last size :"
// + mArrayListWarpViewUndo.get(mArrayListWarpViewUndo.size() - 1)
// .getSize() + 1);
//
// for (int i = 0; i < mArrayListWarpViewUndo.size() - (mArrayListWarpViewUndo.get(mArrayListWarpViewUndo.size() - 1).getSize()+1); i++) {
// if (mArrayListWarpViewUndo.get(i).getMove_x() >= 0 && mArrayListWarpViewUndo.get(i).getMove_y() >= 0) {
// warpPhotoFromC(mArrayListWarpViewUndo.get(i).getImage(),
// mArrayListWarpViewUndo.get(i).getHeight(),
// mArrayListWarpViewUndo.get(i).getWidth(),
// mArrayListWarpViewUndo.get(i).getMax_dist(),
// mArrayListWarpViewUndo.get(i).getOrig_x(),
// mArrayListWarpViewUndo.get(i).getOrig_y(),
// mArrayListWarpViewUndo.get(i).getMove_x(),
// mArrayListWarpViewUndo.get(i).getMove_y());
//
// newBmp.setPixels(mArrayListWarpViewUndo.get(i).getImage(), 0,
// mArrayListWarpViewUndo.get(i).getWidth(), 0, 0,
// mArrayListWarpViewUndo.get(i).getWidth(),
// mArrayListWarpViewUndo.get(i).getHeight());
// fg = false;
// }
// }
//// Log.i(TAG, "Step Size "+mArrayListWarpViewUndo.size()-1);
// mArrayListWarpViewUndo.remove(mArrayListWarpViewUndo.size()-2);
// invalidate();
// }
public class ScaleListener implements OnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
// TODO Auto-generated method stub
Matrix transformationMatrix = new Matrix();
float focusX = detector.getFocusX();
float focusY = detector.getFocusY();
// Zoom focus is where the fingers are centered,
transformationMatrix.postTranslate(-focusX, -focusY);
transformationMatrix.postScale(detector.getScaleFactor(),
detector.getScaleFactor());
/*
* Adding focus shift to allow for scrolling with two pointers down.
* Remove it to skip this functionality. This could be done in fewer
* lines, but for clarity I do it this way here
*/
// Edited after comment by chochim
float focusShiftX = focusX - lastFocusX;
float focusShiftY = focusY - lastFocusY;
transformationMatrix.postTranslate(focusX + focusShiftX, focusY
+ focusShiftY);
mMatrix.postConcat(transformationMatrix);
lastFocusX = focusX;
lastFocusY = focusY;
invalidate();
return true;
}
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
// TODO Auto-generated method stub
lastFocusX = detector.getFocusX();
lastFocusY = detector.getFocusY();
return true;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
// TODO Auto-generated method stub
}
}
public class GestureListener implements OnGestureListener,
OnDoubleTapListener {
@Override
public boolean onDoubleTap(MotionEvent arg0) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onDoubleTapEvent(MotionEvent arg0) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent arg0) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onDown(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
// TODO Auto-generated method stub
return false;
}
@Override
public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
// TODO Auto-generated method stub
if (mIsMove) {
mMatrix.postTranslate(-distanceX, -distanceY);
invalidate();
}
return true;
}
@Override
public void onShowPress(MotionEvent e) {
// TODO Auto-generated method stub
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
}
public void setMove(boolean isMove) {
mIsMove = isMove;
}
// EA VIKALP
public void setWarpBitmap(Bitmap bmp) {
fg = true;// é‡�ç½®æ ‡å¿—
first = 0;
mBmp = bmp;
width = bmp.getWidth();
height = bmp.getHeight();
// 新建�?��Bitmap
// SU VIKALP
// newBmp = Bitmap.createBitmap(width, height,
// Bitmap.Config.RGB_565);
newBmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
// EU VIKALP
image = new int[width * height];
mBmp.getPixels(image, 0, width, 0, 0, width, height);
newBmp.setPixels(image, 0, width, 0, 0, width, height);
// super.setImageBitmap(mBmp);
}
public void setMode(int mode) {
this.MODE = mode;
}
/**
* �?回处�好的图片
*
* @return
*/
public Bitmap getWrapBitmap() {
return newBmp;
}
public void changeBitmapContrastBrightness() {
float contrast, brightness;
Random generator = new Random();
contrast = generator.nextFloat();
brightness = contrast;
// Log.i(TAG, "changeBitmapContrastBrightness " + contrast);
ColorMatrix cm = new ColorMatrix(new float[] {
0.501f, 0, 0, 0,0,// red
0, 0, 0, 0, brightness,// green
0, 0, 0.501f, 0, brightness,// blue
0, 0, 0, 1, 0 // alpha
});
mPaint.setColorFilter(new ColorMatrixColorFilter(cm));
invalidate();
}
}