给GE下载的JPG卫片加配准JGW文件（批量 winform)

jpg地图的空间数据文件-jgw文件格式


1、X-Scale(一个像元的大小)
2、旋转项
3、旋转项
4、负的Y-Scale(一个像元的大小)
5、转换项，即左上角X坐标
6、转换项，即左上角Y坐标

 卫片为256*256大小，文件名以“qrst”串四分

private void button10_Click(object sender, EventArgs e) { if (Directory.Exists(textBox1.Text)) { DirectoryInfo di = new DirectoryInfo(textBox1.Text); foreach (FileInfo fi in di.GetFiles("*.jpg")) { string str = fi.Name.Substring(0, fi.Name.IndexOf(".")); double[] coor = GetCoordinatesFromAddress(str); double[] line = new double[6]; line[0] = (coor[2] - coor[0]) / 256; line[1] = 0; line[2] = 0; line[3] = (-1) * (coor[1] - coor[3]) / 256; line[4] = coor[0]; line[5] = coor[1]; try { FileStream fs = new FileStream(di.FullName + "//"+str+".jgw", FileMode.Create, FileAccess.Write); StreamWriter sw = new StreamWriter(fs); for (int i = 0; i < 6; i++) { sw.WriteLine(line[i].ToString("0.0000000000"));//小数点后保留10位 } sw.Close(); fs.Close(); } catch(Exception ex) { MessageBox.Show(ex.ToString()); } } MessageBox.Show("All Done!"); } } protected double[] GetCoordinatesFromAddress(string str) { // get normalized coordinate first double x = 0.0;//X,Y是以地图的左上角为原点的坐标 double y = 0.0; double scale = 1.0; str = str.Substring(1, str.Length - 1);// skip the first character while (str.Length > 0) { scale *= 0.5; //var c = str.charAt(0);// remove first character char c = str[0]; if (c == 'r' || c == 's') { x += scale; } if (c == 't' || c == 's') { y += scale; } str = str.Substring(1, str.Length - 1); } double[] ret = new double[9]; //qrst地图的0度经纬度是在十字中心,经度出现负数是西经,正数是东经 double long_left = (x - 0.5) * 360; double lat_top = NormalToMercator(y); double long_right = (x + scale - 0.5) * 360; double lat_bot = NormalToMercator(y + scale); double long_cent = (x + scale * 0.5 - 0.5) * 360; double lat_cent = NormalToMercator(y + scale * 0.5); ret[0] = Convert.ToDouble(long_left.ToString("F8")); ret[1] = Convert.ToDouble(lat_top.ToString("F8")); ret[2] = Convert.ToDouble(long_right.ToString("F8")); ret[3] = Convert.ToDouble(lat_bot.ToString("F8")); ret[4] = Convert.ToDouble(long_cent.ToString("F8")); ret[5] = Convert.ToDouble(lat_cent.ToString("F8")); ret[6] = x; ret[7] = y; ret[8] = scale; return ret; } protected double NormalToMercator(double y) { y -= 0.5; y *= 2 * Math.PI; y = Math.Exp(y * 2); y = (y - 1) / (y + 1); y = Math.Asin(y); y = y * -180 / Math.PI; return y; }