Google 使用 OpenCV 将 v2 快照映射到灰度
Google Map v2 snapshot to grayscale using OpenCV
我正在尝试将从 google 地图拍摄的快照转换为灰度（阈值等）但是我不明白 opencv 是如何工作的，我已经成功地实现了它但我不明白人们如何定义什么图像处理，这是我的地图活动代码。
package com.example.admin.pathplaning;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.GoogleMap.SnapshotReadyCallback;
import org.opencv.android.Utils;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import java.io.File;
import java.io.FileOutputStream;
import java.util.Date;
import java.util.Map;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
GPSTracker gps;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
gps = new GPSTracker(MapsActivity.this);
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// Add a marker in operators possition and move the camera
LatLng operator = new LatLng(latitude,longitude);
mMap.addMarker(new MarkerOptions().position(operator).title("Boat Operator"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(operator));
mMap.animateCamera(CameraUpdateFactory.zoomTo(19.0f));
mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng point) {
MarkerOptions marker = new MarkerOptions().position(
new LatLng(point.latitude,point.longitude)).title("Destenation");
mMap.addMarker(marker);
Bitmap bitmap;
SnapshotReadyCallback callback = new SnapshotReadyCallback() {
@Override
public void onSnapshotReady(Bitmap bitmap) {
Date now = new Date();
android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss",now);
try {
String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";
File imageFile = new File(mPath);
FileOutputStream out = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.PNG,90,out);
Log.d("Image:","Saved Snashot. Starting covertion");
String gPath = Environment.getExternalStorageDirectory().toString() + "/" + now + "gray.jpg";
ImageView imgview = (ImageView) findViewById(R.id.imageView);
Bitmap myBitmap = BitmapFactory.decodeFile(mPath);
imgview.setImageBitmap(myBitmap);
Mat mRgba = new Mat();
Mat gray = new Mat(CvType.CV_8UC1);
Imgproc.cvtColor(mRgba,gray,Imgproc.COLOR_BGR2GRAY);
}
catch (Exception e) {
e.printStackTrace();
}
}
};
mMap.snapshot(callback);
Log.d("test","test2");
}
});
}
}
这里是 XML
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.admin.pathplaning.MainActivity">
<fragment
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="149dp"
android:layout_height="match_parent"
tools:context="com.example.admin.pathplaning.MapsActivity"
android:layout_row="0"
android:layout_column="1" />
<ImageView
android:layout_width="209dp"
android:layout_height="485dp"
app:srcCompat="@drawable/cast_abc_scrubber_control_off_mtrl_alpha"
android:id="@+id/imageView" />
</GridLayout>
在这里你可以看到我得到的一个错误，但是，是的，我仍然无法理解发生了什么，即使从 openCV 的文档中也没有，这对我来说真的很新
E/art: No implementation found for long org.opencv.core.Mat.n_Mat()
(tried Java_org_opencv_core_Mat_n_1Mat and
Java_org_opencv_core_Mat_n_1Mat__) D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.admin.pathplaning, PID: 8041
java.lang.UnsatisfiedLinkError: No implementation found for long org.opencv.core.Mat.n_Mat() (tried
Java_org_opencv_core_Mat_n_1Mat and Java_org_opencv_core_Mat_n_1Mat__)
at org.opencv.core.Mat.n_Mat(Native Method)
at org.opencv.core.Mat.(Mat.java:24)
at com.example.admin.pathplaning.MapsActivity.onSnapshotReady(MapsActivity.java:95)
at com.google.android.gms.maps.GoogleMap.zzH(Unknown Source)
at com.google.android.gms.maps.internal.zzag$zza.onTransact(Unknown
Source)
at android.os.Binder.transact(Binder.java:514)
at com.google.android.gms.maps.internal.dn.a(:com.google.android.gms.DynamiteModulesB:117)
at com.google.maps.api.android.lib6.impl.a.a(:com.google.android.gms.DynamiteModulesB:92)
at com.google.maps.api.android.lib6.gmm6.api.y.run(:com.google.android.gms.DynamiteModulesB:2014)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6209)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
D/AppTracker: App Event: crash I/Process: Sending signal. PID: 8041
SIG: 9 Application terminated.
嘿所以经过大量研究我终于明白我做错了什么，我试图将 Nothing 转换为灰色，我找到了我的答案 here
Mat tmp = new Mat (myBitmap.getWidth(), myBitmap.getHeight(), CvType.CV_8UC1);
Utils.bitmapToMat(myBitmap, tmp);
Imgproc.cvtColor(tmp, tmp, Imgproc.COLOR_RGB2GRAY);
Utils.matToBitmap(tmp, myBitmap);
// Utils.matToBitmap(mat1,img);
imgview2.setImageBitmap(myBitmap);
留在这里也许对以后的人有帮助
我正在尝试将从 google 地图拍摄的快照转换为灰度（阈值等）但是我不明白 opencv 是如何工作的，我已经成功地实现了它但我不明白人们如何定义什么图像处理，这是我的地图活动代码。
package com.example.admin.pathplaning;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.GoogleMap.SnapshotReadyCallback;
import org.opencv.android.Utils;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import java.io.File;
import java.io.FileOutputStream;
import java.util.Date;
import java.util.Map;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
GPSTracker gps;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
gps = new GPSTracker(MapsActivity.this);
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// Add a marker in operators possition and move the camera
LatLng operator = new LatLng(latitude,longitude);
mMap.addMarker(new MarkerOptions().position(operator).title("Boat Operator"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(operator));
mMap.animateCamera(CameraUpdateFactory.zoomTo(19.0f));
mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng point) {
MarkerOptions marker = new MarkerOptions().position(
new LatLng(point.latitude,point.longitude)).title("Destenation");
mMap.addMarker(marker);
Bitmap bitmap;
SnapshotReadyCallback callback = new SnapshotReadyCallback() {
@Override
public void onSnapshotReady(Bitmap bitmap) {
Date now = new Date();
android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss",now);
try {
String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";
File imageFile = new File(mPath);
FileOutputStream out = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.PNG,90,out);
Log.d("Image:","Saved Snashot. Starting covertion");
String gPath = Environment.getExternalStorageDirectory().toString() + "/" + now + "gray.jpg";
ImageView imgview = (ImageView) findViewById(R.id.imageView);
Bitmap myBitmap = BitmapFactory.decodeFile(mPath);
imgview.setImageBitmap(myBitmap);
Mat mRgba = new Mat();
Mat gray = new Mat(CvType.CV_8UC1);
Imgproc.cvtColor(mRgba,gray,Imgproc.COLOR_BGR2GRAY);
}
catch (Exception e) {
e.printStackTrace();
}
}
};
mMap.snapshot(callback);
Log.d("test","test2");
}
});
}
}
这里是 XML
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.admin.pathplaning.MainActivity">
<fragment
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="149dp"
android:layout_height="match_parent"
tools:context="com.example.admin.pathplaning.MapsActivity"
android:layout_row="0"
android:layout_column="1" />
<ImageView
android:layout_width="209dp"
android:layout_height="485dp"
app:srcCompat="@drawable/cast_abc_scrubber_control_off_mtrl_alpha"
android:id="@+id/imageView" />
</GridLayout>
在这里你可以看到我得到的一个错误，但是，是的，我仍然无法理解发生了什么，即使从 openCV 的文档中也没有，这对我来说真的很新
E/art: No implementation found for long org.opencv.core.Mat.n_Mat() (tried Java_org_opencv_core_Mat_n_1Mat and Java_org_opencv_core_Mat_n_1Mat__) D/AndroidRuntime: Shutting down VM E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.admin.pathplaning, PID: 8041 java.lang.UnsatisfiedLinkError: No implementation found for long org.opencv.core.Mat.n_Mat() (tried Java_org_opencv_core_Mat_n_1Mat and Java_org_opencv_core_Mat_n_1Mat__) at org.opencv.core.Mat.n_Mat(Native Method) at org.opencv.core.Mat.(Mat.java:24) at com.example.admin.pathplaning.MapsActivity.onSnapshotReady(MapsActivity.java:95) at com.google.android.gms.maps.GoogleMap.zzH(Unknown Source) at com.google.android.gms.maps.internal.zzag$zza.onTransact(Unknown Source) at android.os.Binder.transact(Binder.java:514) at com.google.android.gms.maps.internal.dn.a(:com.google.android.gms.DynamiteModulesB:117) at com.google.maps.api.android.lib6.impl.a.a(:com.google.android.gms.DynamiteModulesB:92) at com.google.maps.api.android.lib6.gmm6.api.y.run(:com.google.android.gms.DynamiteModulesB:2014) at android.os.Handler.handleCallback(Handler.java:751) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6209) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) D/AppTracker: App Event: crash I/Process: Sending signal. PID: 8041 SIG: 9 Application terminated.
嘿所以经过大量研究我终于明白我做错了什么，我试图将 Nothing 转换为灰色，我找到了我的答案 here
Mat tmp = new Mat (myBitmap.getWidth(), myBitmap.getHeight(), CvType.CV_8UC1);
Utils.bitmapToMat(myBitmap, tmp);
Imgproc.cvtColor(tmp, tmp, Imgproc.COLOR_RGB2GRAY);
Utils.matToBitmap(tmp, myBitmap);
// Utils.matToBitmap(mat1,img);
imgview2.setImageBitmap(myBitmap);
留在这里也许对以后的人有帮助