Sharpmap Analysis Note for. NET 2.0-based open-source GIS project (11): sharpmap image preparation-geotiff image production process based on ERDAS

SharpMap Analysis Note for. NET 2.0-based open-source GIS project (11): SharpMap image preparation-GEOTIFF image production process based on ERDAS

Su Weimin http://www.gisdev.cn/http://blog.csdn.net/suen/ date: 2007-7-5

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SharpMap supports images through the GDAL extension. NET 2.0 GIS open source project SharpMap Analysis Note (7): gdal c # interface library compilation and SharpMap (Change Set 21021) the article on image support completes a compilation and running version that supports both vector data and images. Here we will talk about the production process of image data based on ERDAS.

There are several steps:

(1) Save your image in BMP, PNG, or TIF format;

(2) Open your correct image in the viewer Module

(3) Save the image in ERDAS. img format

(4) Click the dataprep module to open the image geometric correction submodule under it,

(5) Select from image file, select the image you want to configure, and open

(6) In the set geometric model that appears, select 2nd polyonial

(7) In the following dialog box, there is a polynomial order. Generally, you can select 1 or 2. 2 requires 6 configuration points.

(8) then apply and in the close dialog box

(9) Select the first dialog box in the following dialog box and a small dialog box appears. Click the correct image interface in the first step to complete registration.

(10) Click a point in your accurate image and go to the image you want to match to find a point similar to him. Click here and select 6 points, on the gcp tool interface, there will be error parameters. You can see if your points are accurate. These six points are control points, so you should split them out when you select them. Try to find them in the full graph range. Then, the more points you select, the better.

(11) If you don't want to find it that way, you can right-click any image and select geo. Link/unlink option. In that case, you only need to point in one image, and the machine will automatically find it in the other. However, no error parameters will appear in the first six points, the error parameter will appear from the seventh point. If the error is too large, you must modify

(12) After configuration, click the 3rd icons in geo correction tools to save the registered image.

(13) If you need to take a break during registration, you need to save the gcp tools dialog box and open it directly in the next match.

(14) The total error after registration, that is, the rms error must be in the 0.5 pixels

(15) use the IMPORT/EXPORT tool to convert. img images to GEOTIFF images.