Googleearth screenshot skills)

When we need image data

The first thing that comes to mind is getting some data from Google Earth.

However, if the downloaded area is large, it is usually found that there is a gap or dislocation between the data edge.

The main cause is the inconsistency between the GE window and the getscreen window.

Network-related solutions:

1. Set the moving speed in GE to a lower value. The safest way is to use the default setting of Ge;

2. In Ge, turn off the "terrain" display, otherwise there will be misplacement in non-flat areas;

3. Tools> Options> 3D views: "DirectX" and "use security mode ";

Note:

1. run GE first. Be sure to run GE with driectx mode. Find the desired range before running it.

Getscreen.

2. Do not close the left sidebar of GE. Adjust the width of the left sidebar of GE to the width of the left sidebar of getscreen.

Wait

The image capture latency is set to 500.

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The above method should be able to successfully download images, but these are just some raw materials. To use them, you have

Processing --- coordinate assignment

Method 1: Use globemapper

Add data to globemapper one by one, and then use the export tool to output data in IMG or Tif format.

There will be coordinates.

Method 2: manually assign coordinates to images (for JPG data)

After the captured image is processed as a JPG file, there is also a map file that records the image information.

The map file records the following information:

[Mmp xy, 0
Mmp xy, 2,1952, 0
Matrix, 1720, <1> image size (W

, H)
Mmp xy, 1720
Mmpll, 1,115.351188, 41.155466 <2> Coordinate System in the upper left corner (Minx, Maxy

)
Mmpll, 2,118.048764, 41.155466
Mmpll, 3,118.048764, 39.326317 <3> coordinate system (Maxx, miny

)
Mmpll, 4,115.351188, 39.326317]

A jpg image must have a jgw coordinate file similar to the TIF number.

Data tfw File

The following information is recorded:

A: X-axis resolution-the size of a pixel in the X direction
B: 0 ---> usually 0
C: 0 ---> usually 0
D: Y-axis resolution-size of a pixel in the Y direction
E: the horizontal coordinates of the first pixel center in the upper left corner.
F: Map ordinate of the first pixel center in the upper left corner

In this way, you can manually write the jgw file based on the preceding values.

A = (Maxx-Minx)/W
B = 0
C = 0
D = (miny-Maxy)/h
E = Maxx
F = miny

After such calculation, the captured data has coordinates!

Problems encountered by netizens:

[We set the height of the "getscreen-Automatic screenshot tile tool" to 250, but the final result is

The resulting image is equivalent to the size seen at the ge356 m height. Although this small problem is true for most

There is no impact on the application, but it will bring a lot of trouble when using quantitative (fixed size) plotting.

After careful consideration, it was found that the reason was: getscreen "hijacked" GE's full range to that window, the original level

The 1024dpi image is compressed to the 722dpi window, resulting in a rate compression. In this way, I

The screenshots taken after screenshots are smaller than those displayed at the same height on the GE screen.
How can we keep the image captured by the "getscreen-Automatic screenshot tile tool" at a predetermined height with Ge?

What is the same size on? This requires correction based on the difference between the two during screenshot capture. 722/1024 = 0.705,

This is the correction coefficient. For example, if we want to make the screenshot image as big as the ge250 meters

The height of getscreen screenshots should be set to 250*0.705 = 176 meters. Actual Ge height *

0.705 = getscreen height]

From http://blog.3snews.net/html/69/12969-26152.html