ArcGIS image solution (2)-Qa

0 ArcGIS image management common QA

Software environment: ArcGIS SP2 beta version

Image Data source: zy3 Satellite Data

Problems encountered during image processing:

1. Problems with displaying part of the image data after the mosaic dataset is created

2. Slice management in the process of data set updating

3. Select the deployment method of the embedded dataset Service

4. Automatic post-registration of embedded Datasets

5. Image Data Fusion and export Distortion

 

The following describes the specific problems, including the problem description, causes, and solutions.

1. Question 1.1 displayed by some image data departments after the dataset is created

After the mosaic dataset is created, after image data is added, some images are gray, white, or not displayed?

1.2 cause

The main cause of this problem is the size range of the image.

Basic Principles

The pixel size range is used to determine which raster is used from the mosaic data set to create a dynamic mosaic image. View the mosaic dataset Attribute Table to view the pixel size of the grid. The lowps and hightps fields define the actual range of the pixel size contained in the grid dataset; the minps and maxps columns define the object size range. The grid dataset used is determined based on the range.

When a raster dataset is added to an embedded dataset, the object size value is filled with the unit defined by the Space reference of the embedded dataset. These object sizes are only used to identify the range of object sizes and are not used to perform geographic registration on the raster. Therefore, the accuracy of lowps and hightps values is not important.

The minps and maxps columns define the object size range. The grid dataset used is determined based on the range. If you select the "add grid to embedded dataset" option, or use the "computing pixel size range" option, these values are filled, you can also manually edit the values in the table. Calculate the value of minps and maxps Based on the superposition between the pyramid (overview) and the image.

The pixel size is used in the mosaic data set, rather than the proportion, because the pixel size is an inherent value of the raster data set.

The minimum pixel size defines the lower limit of the image. Therefore, you cannot process any image requests lower than this value. The default value is 0, but you can set it to a larger value to limit the resolution of accessible images. If a request is sent below this Resolution, the request fails and no image is returned.

The maximum pixel size defines the upper limit of the image. Therefore, you cannot process any image requests higher than this value. Different from the default value of the minimum pixel size, the default value of the maximum pixel size is a large number. If a request is sent higher than this Resolution, the request fails and a gray image is returned.

1.3 Solution

Method 1: set the minimum number of rows or columns in the raster pyramid option when adding a raster to mosaic data. The experience value is 200, which can be set according to different precision images.

Method 2: Modify the maxps and minps values in the contour Attribute Table In ArcMap.

For example, the effect of the normal setting of the object size and the corresponding value

After you modify maxps, if you set the maximum object meta value to 20, the image is not displayed when the request exceeds 20 meters.

2. Choose 2.1 as the deployment method of the embedded dataset service. Problem description.

Two scenarios are taken into account when users publish the image service. One is the image Service released within the LAN. Users can perform analysis and download operations based on the Image Service. The other is Internet users, you cannot view the above features.

2.2 Solution

The solution is to use the image cache service in the LAN and the map slicing service on the Internet.

The image service in the LAN is directly released as the image service. You can set the function during the release process.

Set the slicing Scheme

After that, the Slice Image Service is published.

For services published on the public network, create a polygon with a visible range In ArcMap, publish the map service, select publish service, and manually build the cache, copy the previously cut image and cache it to/arcgisserver/directories/arcgiscache to overwrite the content of the just-released Service. The process is similar to the deployment of gitlab raster data.

3. Post-processing of Automatic Image Registration 3.1 Problem Description

Deviations after Automatic Image Registration

3.2 cause

Image precision, offset, angle, and other reasons

3.3 Solution

Method 1: superimposed DEM for correction;

Method 2: Use the "registerraster" tool to register the raster tool and perform geographic transformation on the existing raster dataset by automatically registering the reference image.

By: Mhy