MeteoInfo-Java解析與繪圖教程(四)
上文我們說到,將地圖疊加在色斑圖上,但大部分都是衛星繪圖,現在開始講解micaps數據繪圖,同樣也是更多自定義配置
首先我們解析micaps數據,將之前學到的東西拿過來繪圖
MeteoDataInfo meteoDataInfo = new MeteoDataInfo();
meteoDataInfo.openMICAPSData("D:\\解析數據\\cldas\\cldas\\TEM\\20081000.000");
GridData grid = meteoDataInfo.getGridData();
//讀取地圖A
VectorLayer scmap = MapDataManage.readMapFile_ShapeFile("E:\\shp\\四川\\四川省(3)_市界.shp");
//描述地圖邊界線
PolygonBreak pb = (PolygonBreak) scmap.getLegendScheme().getLegendBreak(0);
//是否設置填充
pb.setDrawFill(false);
//設置輪廓大小
pb.setOutlineSize(2f);
//設置輪廓顏色
pb.setOutlineColor(Color.black);
//讀取色階
LegendScheme als = LgsUtil.readFromLgs("D:\\apache-tomcat-8.0.50\\alt色階\\color\\ECMWF_HR\\TMP.lgs");
//繪制圖層
VectorLayer layer = DrawMeteoData.createShadedLayer(grid,als,"","",true);
//創建視圖
MapView view = new MapView();
//疊加圖層
view.addLayer(layer);
view.addLayer(scmap);
MapLayout layout = new MapLayout();
//去除圖形邊框
layout.getActiveMapFrame().setDrawNeatLine(false);
//區域邊界
Extent extent = view.getExtent();
//設置矩形的寬和高
Rectangle bounds = new Rectangle(800, (int) (800 * 1D / extent.getWidth() * extent.getHeight()));
//設置地圖邊框
layout.setPageBounds(new Rectangle(0, 0, bounds.width, bounds.height));
//設置頁面邊框
layout.getActiveMapFrame().setLayoutBounds(new Rectangle(0, 0, bounds.width, bounds.height));
layout.getActiveMapFrame().setMapView(view);
layout.exportToPicture(PathUtil.getDeskPath()+"/1.png");
可以看出來,micaps繪圖和衛星繪圖的區別只在解析數據openData的方法上,以及繪制圖層createShadedLayer上,這個方法是繪制色斑圖(等值圖),而createContourLayer是繪制等值線,可以切換試一試
當然實際使用的時候,圖一定是不需要這種的,例如四川的數據就應該只在四川區域呈現,其他區域就為空白,這里就涉及到了地圖切割,可以將圖層按照地圖邊界切割掉
MeteoDataInfo meteoDataInfo = new MeteoDataInfo(); meteoDataInfo.openMICAPSData("D:\\解析數據\\cldas\\cldas\\TEM\\20081000.000"); GridData grid = meteoDataInfo.getGridData(); //讀取地圖A VectorLayer scmap = MapDataManage.readMapFile_ShapeFile("C:\\Users\\Administrator\\Downloads\\好例子網_全國省、縣界線shp格式矢量圖（精確到縣區域）\\全國省、縣界線shp格式矢量圖（精確到縣區域）\\sichuan.shp"); //讀取色階 LegendScheme als = LgsUtil.readFromLgs("D:\\apache-tomcat-8.0.50\\alt色階\\color\\ECMWF_HR\\TMP.lgs"); //繪制圖層 VectorLayer layer = DrawMeteoData.createShadedLayer(grid,als,"","",true); //創建視圖 MapView view = new MapView(); layer = layer.clip(scmap); //疊加圖層 view.addLayer(layer); MapLayout layout = new MapLayout(); //去除圖形邊框 layout.getActiveMapFrame().setDrawNeatLine(false); //區域邊界 Extent extent = view.getExtent(); //設置矩形的寬和高 Rectangle bounds = new Rectangle(800, (int) (800 * 1D / extent.getWidth() * extent.getHeight())); //設置地圖邊框 layout.setPageBounds(new Rectangle(0, 0, bounds.width, bounds.height)); //設置頁面邊框 layout.getActiveMapFrame().setLayoutBounds(new Rectangle(0, 0, bounds.width, bounds.height)); layout.getActiveMapFrame().setMapView(view); //圖片存放地址 String imagePath = PathUtil.getDeskPath()+"/1.png"; layout.exportToPicture(imagePath); //透明處理 //讀取圖片 BufferedImage bi = ImageIO.read(new File(imagePath)); //類型轉換 BufferedImage img = new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_INT_ARGB); Graphics2D g = (Graphics2D) img.getGraphics(); g.drawImage(bi, null, 0, 0); //透明處理 int alpha = 0; for(int i=img.getMinY(); i<img.getHeight(); i++){ for(int j=img.getMinX(); j<img.getWidth(); j++){ int rgb = img.getRGB(j, i); //透明部分不需要處理 if(rgb < 0){ int R = (rgb & 0xff0000) >> 16; int G = (rgb & 0xff00) >> 8; int B = (rgb & 0xff); //將白色剔除 Color color = Color.white; if(color.getRed() == R && color.getGreen() == G && color.getBlue() == B){ alpha = 0; } else { alpha = 255; } rgb = (alpha << 24) | (rgb & 0x00ffffff); img.setRGB(j, i, rgb); } } } //釋放資源 g.dispose(); ImageIO.write(img, "png", new File(imagePath));
首先我們需要注意到的是shp文件，如果不知道如何下載shp，可以直接去好例子網下載shp，現成的，很方便，這個shp文件我們需要的是省界，文件里面不要有市的信息，否則無法截個邊緣
第二點，我們將白色做了透明處理，這樣就成為了氣象行業需要的貼圖了，透明處理可以集成一個方法，我單純是為了方便才這樣寫
有一些時候我們需要在圖上看到城市邊界，此時我們就可以在加一個市界圖層，將圖層疊上去
MeteoDataInfo meteoDataInfo = new MeteoDataInfo();
meteoDataInfo.openMICAPSData("D:\\解析數據\\cldas\\cldas\\TEM\\20081000.000");
GridData grid = meteoDataInfo.getGridData();
//讀取地圖A
VectorLayer scmap = MapDataManage.readMapFile_ShapeFile("C:\\Users\\Administrator\\Downloads\\好例子網_全國省、縣界線shp格式矢量圖（精確到縣區域）\\全國省、縣界線shp格式矢量圖（精確到縣區域）\\sichuan.shp");
//讀取地圖B
VectorLayer qgmap = MapDataManage.readMapFile_ShapeFile("E:\\shp\\四川\\四川省(3)_市界.shp");
//描述地圖邊界線
PolygonBreak pb = (PolygonBreak) qgmap.getLegendScheme().getLegendBreak(0);
//是否設置填充
pb.setDrawFill(false);
//設置輪廓大小
pb.setOutlineSize(2f);
//設置輪廓顏色
pb.setOutlineColor(Color.black);
//讀取色階
LegendScheme als = LgsUtil.readFromLgs("D:\\apache-tomcat-8.0.50\\alt色階\\color\\ECMWF_HR\\TMP.lgs");
//繪制圖層
VectorLayer layer = DrawMeteoData.createShadedLayer(grid,als,"","",true);
//創建視圖
MapView view = new MapView();
layer = layer.clip(scmap);
//疊加圖層
view.addLayer(layer);
view.addLayer(qgmap);
MapLayout layout = new MapLayout();
//去除圖形邊框
layout.getActiveMapFrame().setDrawNeatLine(false);
//區域邊界
Extent extent = view.getExtent();
//設置矩形的寬和高
Rectangle bounds = new Rectangle(800, (int) (800 * 1D / extent.getWidth() * extent.getHeight()));
//設置地圖邊框
layout.setPageBounds(new Rectangle(0, 0, bounds.width, bounds.height));
//設置頁面邊框
layout.getActiveMapFrame().setLayoutBounds(new Rectangle(0, 0, bounds.width, bounds.height));
layout.getActiveMapFrame().setMapView(view);
//圖片存放地址
String imagePath = PathUtil.getDeskPath()+"/1.png";
layout.exportToPicture(imagePath);
//透明處理
//讀取圖片
BufferedImage bi = ImageIO.read(new File(imagePath));
//類型轉換
BufferedImage img = new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g = (Graphics2D) img.getGraphics();
g.drawImage(bi, null, 0, 0);
//透明處理
int alpha = 0;
for(int i=img.getMinY(); i<img.getHeight(); i++){
for(int j=img.getMinX(); j<img.getWidth(); j++){
int rgb = img.getRGB(j, i);
//透明部分不需要處理
if(rgb < 0){
int R = (rgb & 0xff0000) >> 16;
int G = (rgb & 0xff00) >> 8;
int B = (rgb & 0xff);
//將白色剔除
Color color = Color.white;
if(color.getRed() == R && color.getGreen() == G && color.getBlue() == B){
alpha = 0;
}
else {
alpha = 255;
}
rgb = (alpha << 24) | (rgb & 0x00ffffff);
img.setRGB(j, i, rgb);
}
}
}
//釋放資源
g.dispose();
ImageIO.write(img, "png", new File(imagePath));
補充工具類說明:
public static LegendScheme readFromLgs(String path) throws Exception { LegendScheme scheme = new LegendScheme(); scheme.importFromXMLFile(path, false); return scheme; }