我拍摄了谷歌地球的图像,其中所有4个角落的纬度/经度都是已知的。我正在使用GPS传感器捕获纬度/经度。我必须使用java将这些捕获的纬度/经度转换为图像坐标(像素坐标)。我将使用图像坐标来模拟车辆在静态地图上移动(从Google地球拍摄的图像)。
我找到了这个公式并试图实现它
J =输入经度 K =输入纬度
计算X像素
XPixel = CInt(((Y - J) / CDbl(Z)) * 1653)
计算Y像素
YPixel = CInt(((A - K) / CDbl(C)) * 1012)
这是我使用的代码。
import java.awt.geom.Point2D;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;
public class LatLongService {
private static LatLongService latLangService;
private BufferedReader reader = null;
private String st;
private LatLongService() {
try {
reader = new BufferedReader(new FileReader(new File(
"resources/GPS_lat_long_2.txt")));
} catch (Exception e) {
e.printStackTrace();
}
}
public static LatLongService getInstance() {
if (latLangService == null)
latLangService = new LatLongService();
return latLangService;
}
public List<Point2D> readLatLongList() {
List<Point2D> pointList = new ArrayList<Point2D>();
StringBuffer xStr;
StringBuffer yStr = new StringBuffer();
try {
while ((st = reader.readLine()) != null) {
xStr = new StringBuffer(st.substring(0, st.indexOf(',')));
yStr = new StringBuffer(st.substring(st.indexOf(',') + 2,
st.length()));
Point2D pt = new Point2D.Double(
new Double(xStr.toString()).doubleValue(), new Double(
yStr.toString()).doubleValue());
pointList.add(pt);
}
} catch (Exception e) {
e.printStackTrace();
try {
reader.close();
} catch (Exception e2) {
e.printStackTrace();
}
}
return pointList;
}
public List<Point2D> convertLatLongToCoord(List<Point2D> coordinate) {
List<Point2D> latLong = new ArrayList<Point2D>();
double westMostLong = -79.974642;
double eastMostLong = -79.971244;
double longDiff = eastMostLong - westMostLong; // (rightmost_longitude -
// leftmost_longitude)
double northMostLat = 39.647556;
double southMostLat = 39.644675;
double latDiff = northMostLat - southMostLat; // (topmost_latitude -
// bottommost_latitude)
for (Point2D coord : coordinate) {
double j = coord.getY();
double k = coord.getX();
double XPixel = (((eastMostLong - j) / longDiff) * 1653);
double YPixel = (((northMostLat - k) / latDiff) * 1012);
Point2D actualCoord = new Point2D.Double(XPixel, YPixel);
latLong.add(actualCoord);
}
return latLong;
}
}
我从GPS传感器获得的一些GPS lat / long
输入纬度输入经度 (39.64581,-79.97168) (39.64651,-79.97275) (39.646915,-79.97342) (39.646538,-79.97279)
[IMG] http://i59.tinypic.com/nbqkk3.png[/IMG]
图中的红线表示传感器拍摄GPS坐标时的路径。
但是,当我使用此公式将Lat / Long坐标转换为像素坐标时。转换后的像素坐标不一致,如下所示:
图像X图像Y. (212.0977045,613.3120444) (732.6127134,367.4251996) (1058.542672,225.1620965) (752.0712184,357.5897258)
X,Y(像素)坐标的变化太大。因此,当我尝试基于像素坐标移动车辆时,车辆不遵循红线或至少接近红线。
车辆在红线上方或线下方移动,但不在线上移动。
为了使基于像素坐标的车辆平稳移动,理想情况下我希望从纬度/长度到图像坐标的转换是这样的:
必需图像X必需图像Y. (1290,409) (1289,409) (1288,409) (1287,409)
但我得到了这个
图像X图像Y. (212.0977045,613.3120444) (732.6127134,367.4251996) (1058.542672,225.1620965) (752.0712184,357.5897258)
我希望我能够传达我的问题。
答案 0 :(得分:1)
纬度和经度不是距离。
http://geography.about.com/cs/latitudelongitude/a/latlong.htm
我最近参与了一个使用GPS的Arduino项目。我遵循minigeo API方法,将纬度和经度转换为北向和东向(UTM)。
使用链接中的库可以执行此转换: http://www.ibm.com/developerworks/library/j-coordconvert/
获得最大东移和北移并计算比例
private synchronized void scale() {
int w = 800;
int h = 600;
this.scale = Math.min(
w / (maxEasting - minEasting),
h / (maxNorthing - minNorthing));
oEasting = minEasting;
oNorthing = minNorthing;
}
转换为X和Y
private int applyScale(double km) {
return (int) (km * scale);
}
private int convertX(double easting) {
return applyScale(easting - oEasting);
}
private int convertY(double northing, int height) {
return 600/*height*/ - applyScale(northing - oNorthing);
}
来源:Minigeo
答案 1 :(得分:0)
以下是编译和回答您的问题的代码
[1] (39.64581,-79.97168) -> 102,363
[2] (39.64651,-79.97275) -> 354,217
[3] (39.646915,-79.97342) -> 512,133
[4] (39.646538,-79.97279) -> 363,212
[5] (39.646458,-79.97264) -> 328,228
您可能已经互换了x-y坐标。在这种情况下,x ==经度,y ==纬度。
import java.util.*;
import java.awt.geom.*;
public class LatLong {
private int imageW, imageH;
private final static double west = -79.974642, north = 39.647556,
east = -79.971244, south = 39.644675;
public LatLong (int w, int h) {
imageW = w;
imageH = h;
}
public List<Point2D> convertLatLongToCoord (List<Point2D> coordinate) {
List<Point2D> latLong = new ArrayList<Point2D>();
for (Point2D coord : coordinate) {
double x = coord.getY(), px = imageW * (x-east) / (west-east),
y = coord.getX(), py = imageH * (y-north)/(south-north);
latLong.add (new Point2D.Double(px,py));
}
return latLong;
}
public static void main (String[] args) {
double[] latit = {39.64581, 39.64651, 39.646915, 39.646538, 39.646458},
longit = {-79.97168, -79.97275, -79.97342, -79.97279, -79.97264};
List<Point2D> pointList = new ArrayList<Point2D>();
for (int i = 0 ; i < latit.length ; i++)
pointList.add (new Point2D.Double(latit[i], longit[i]));
List<Point2D> pixels = new LatLong (800,600).convertLatLongToCoord (pointList);
for (int i = 0 ; i < latit.length ; i++)
System.out.println ("[" + (i+1) + "]\t(" + latit[i] + "," + longit[i] + ") -> " +
(int) (pixels.get(i).getX()) + "," + (int) (pixels.get(i).getY()));
}}