Generate Orthophotos

Instructions For Use

A Digital Orthophoto Map (DOM), referred to as an orthophoto, is an image dataset generated through the vertical projection of aerial or spaceborne imagery. During the vertical projection process, the system eliminates geometric distortions caused by factors such as terrain relief and camera tilt, endowing the orthophoto with uniform geometric accuracy. Additionally, orthophotos can be seamlessly overlaid with maps, vector data, etc., providing reliable support for precise spatial analysis and measurement. Generating orthophotos refers to the process of outputting these processed image datasets.

In the process workflow, only the panchromatic orthophoto is output by default.

SuperMap iDesktopX supports this function starting from version 11i(2023).

Parameter Description

Parameter Name Parameter Interpretation Parameter Type
Dataset

Displays the original image used for generating the panchromatic orthophoto. It is not editable.

 DatasetMosaic
Export Directory Uses the Processing Path parameter from Set Image Path. It is not editable. File
Resolution Type

Specifies the method for determining the output image resolution. The default is Original Resolution.

  • Original Resolution: Retains the original resolution of the input image.
  • Fixed Value: Uses the input fixed value as the output image resolution.
  • Custom: Outputs different resolutions based on different satellite sensor types. Selecting the Custom option will pop up the Custom Resolution: dialog box. You can click the Add button on the toolbar to add a new record. Then click the cell in the Satellite Sensor Type column to select a sensor type. Finally, enter the resolution corresponding to the sensor type in the cell of the Resolution column.
    Note:
    • If the corresponding satellite sensor type is not found, please select the USEDEFINE option. After selecting this option, the system will use the resolution corresponding to USEDEFINE to output data from all unsupported satellite sensor types.
    • If processing image data from multiple satellite sensor types simultaneously (e.g., ZY3, GF-2, LandSat) but only setting the resolution for one type (e.g., only setting ZY3's resolution), images from other sensor types (e.g., GF-2 and LandSat) will be output using their original resolution.
 OrthoRatioType
Coordinate System Settings Uses the Output Coordinate System parameter from Set Image Path. It is not editable. PrjCoordSys
Output Format Uses the Output Format parameter from Set Image Path. It is not editable. FileType
Compression Method Uses the Compression Method parameter from Set Image Path. It is not editable. CompressMethod
Downscale To 8-Bit Unsigned

Specifies whether to convert the image's pixel format to 8-bit unsigned before output.

By default, this is unchecked, meaning no pixel format conversion is performed; the original image's pixel format is used for output, ensuring lossless data accuracy.

If checked, the output image's pixel format will be converted to 8-bit unsigned according to the specified stretch method. This processing can reduce storage space and improve efficiency but may cause issues like overexposure or information loss, potentially affecting subsequent imagery and analysis.

 Boolean
Stretch Method Available after checking Downscale To 8-Bit Unsigned. Default is Percent Clip. Also provides Minimum Maximum, Gaussian, Gamalashin, Histogram Equalization, and Logarithmic Stretch. For more method introductions, please refer to Image Stretching Methods. DesktopImageStretchingType
Minimum Percentage

Available when Stretch Method is Percent Clip. Default value is 1.

 Double
Maximum Percentage Available when Stretch Method is Percent Clip. Default value is 99. Double
Gaussian Standard Deviation Coefficient Available when Stretch Method is Gaussian. Default value is 3. Integer
Gamma Stretch Parameter Available when Stretch Method is Gamalashin. Default value is 0.5. Double
Create Image Pyramid Checked by default. Builds pyramids for the image data according to the specified resampling method, thereby improving image zoom display rendering and performance. Boolean
Resampling Method Available after checking Create Image Pyramid. Default is Average. For more method introductions, please refer to Resampling Method. PyramidResampleType
Asynchronously Create Statistics During image browsing, the layer will be stretched based on statistics information. If the image lacks statistics information, it will be displayed using the default stretch method, and 8-bit data will not be stretch displayed. Checked by default, meaning statistics will be created for the image in the background without affecting process execution. If unchecked, statistics will be created while executing this tool, which may consume time. Boolean

Output Result

  • Outputs the panchromatic image data processed by orthorectification to the local folder.
  • Automatically creates an OrthoPanmosaic dataset in the OrthoData datasource based on the panchromatic image data.

Related Topics

Block Adjustment

Multispectral And Panchromatic Registration

Image Fusion