True Color Output

Feature Description

True color output refers to the process of using image stretching and image enhancement techniques to improve the display effects of images, making their colors closer to the actual colors of ground objects. At the same time, this process converts the image into a three-band 8-bit unsigned pixel format for output, facilitating subsequent imagery and visual display.

The true color output result can display surface features in a way close to their real colors, thus playing an important role in fields such as urban planning, land use classification, agricultural monitoring, map production and updating.

Parameter Description

Parameter Parameter Interpretation Parameter Type
Data Type

This parameter is available only when the function is launched from the Satellite Image Processing tab -> DOM Data Production group -> True Color Output.

Select the source of input image data. Provides two options: Image Files and Mosaic Dataset. The default is Image Files.

Image Files

This parameter is available only when the function is launched from the Satellite Image Processing tab -> DOM Data Production group -> True Color Output.

After selecting Image Files in Data Type, you can directly enter the local path information, and all images under that path will be automatically retrieved.

File
Image Data Source

This parameter is available only when the function is launched from the Satellite Image Processing tab -> DOM Data Production group -> True Color Output.

After selecting Mosaic Dataset in Data Type, specify the data source where the image dataset is located.

Datasource
Image Data After selecting Mosaic Dataset in Data Type, specify the image dataset. If it is for workflow production, only the dataset is displayed and cannot be edited. DatasetMosaic
Red Band Index Set the red band, default is 2. Integer
Green Band Index Set the green band, default is 1. Integer
Blue Band Index Set the blue band, default is 0. Integer
Near-Infrared Spectroscopy (NIR) Index Set the near-infrared band, not set by default. This parameter is required when vegetation enhancement is needed. Integer
Automatically Calculate Truncation Percentage

Specify whether to perform image stretching using the Percent Clip method, unchecked by default.

  • Checked: Automatically calculate the truncation percentage based on the brightness of the image, and perform percent clip according to the calculated result.
  • Unchecked: Calculate the image stretching result based on the maximum/minimum truncation percentage.
Boolean
Minimum Truncation Percentage

Available when Automatically Calculate Truncation Percentage is unchecked.

Set the minimum truncation percentage value for image linear extrusion, with a range of [0,100], default is 0.2.

Double
Maximum Truncation Percentage

Available when Automatically Calculate Truncation Percentage is unchecked.

Set the maximum truncation percentage value for image linear extrusion, with a range of [0,100], default is 99.8.

Double
Highlighted White Spot Threshold

Available when Automatically Calculate Truncation Percentage is checked.

When performing image stretching, if the area of highlighted white spots in the image is greater than the specified area threshold, the truncation percentage is considered too large. Otherwise, it is considered that the truncation percentage can be further increased.

Default is 20000, unit is m\u00B2. If there are fewer highlighted areas in the image, it is recommended to increase this parameter to obtain higher contrast.

Double
Use Gamma Correction

Use gamma correction to achieve non-linear brightness and contrast adjustment of the image, thereby enhancing image display details and improving the display quality of image data.

Unchecked by default, i.e., gamma correction is not used to improve the display quality of image data.

If this checkbox is checked, you need to select the gamma correction method.

Boolean
Gamma Correction

Available when Use Gamma Correction is checked. Provides two methods: Adaptive and Custom, default is Adaptive.

  • Adaptive: The system will automatically adjust the gamma values of the red, green, and blue bands based on the image.
  • Custom: You need to set the gamma values for the red, green, and blue bands respectively, all default to 1.5, with a range of (0-10].
    • When the gamma value is 1, the image has not undergone gamma correction.

    • When the gamma value is greater than 1, the contrast in the dark areas of the image increases, making details more prominent, but details in the bright areas may be lost, and the overall image becomes brighter.
    • When the gamma value is less than 1, the contrast in the bright areas of the image increases, making details more prominent, but details in the dark areas may be lost, and the overall image becomes darker.
GammaCorrectMethod
Vegetation Enhancement

Available when the red, green, blue, and near-infrared band indices are all non-empty.

Used to enhance the display effects of vegetation areas, unchecked by default, i.e., vegetation enhancement is not used.

Boolean
NDVI Threshold

Available when Vegetation Enhancement is checked.

Used to determine the vegetation range. When the NDVI threshold is greater than the NDVI value of the image, vegetation enhancement is activated. Default is 0.0, NDVI = (NIR - Red) / (NIR + Red).

Double
Green Band Weight

Available when Vegetation Enhancement is checked.

Set the weight of the green band during vegetation enhancement, with a range of [0,1], default is 0.7. The sum of green band weight and near-infrared weight must be 1.

Double
Near-Infrared Weight

Available when Vegetation Enhancement is checked.

Set the weight of the near-infrared band during vegetation enhancement, with a range of [0,1], default is 0.3. The sum of green band weight and near-infrared weight must be 1.

Double
Contrast Enhancement When the contrast of the image is low or when using automatically calculate truncation percentage, it is recommended to use contrast enhancement to improve the display effects of the image. This checkbox is checked by default. Boolean
Contrast Limit

Available when Contrast Enhancement is checked.

Indicates the degree of contrast enhancement, the larger the value, the greater the enhancement. Default is 1.5.

Double
Mask Data

Unchecked by default. If checked and mask data is set, the system will exclude this area before outputting the true color image.

Boolean
Source of Data Available when Mask Data is checked. The cloud amount data can be obtained through Existing Data or Cloud Detection, default is Existing Data. CloudMaskDataSourceType
Datasource Available when Existing Data is selected in Source of Data. Specify the data source where the mask dataset is located. DataSource
Dataset Available when Existing Data is selected in Source of Data. Specifies the mask dataset. The ImageName field must be included in the dataset, and the name must correspond to the current pending image name. DatasetVector
Mask Pixel Threshold

Available when Cloud Detection is selected in Source of Data.

The minimum number of pixels to retain for the mask. If the number is greater than this threshold, the area is judged as a cloud area; if less than this threshold, it is judged as a non-cloud area and the mask data is not retained. Default is 4096.

Integer
Output Format

Set the storage type of the result image. Provides four options: Not Set, Tiff/GeoTIFF, Erdas Image, and PCIDSK. Default is Tiff/GeoTIFF, indicating output using the original storage type of the image.

If executing a production workflow, the Output format parameter from Set Image Path or Add Orthophoto is used, and this parameter is not editable.

FileType
Compression Method

Set the compression method of the output image. Only available when output format is Tiff/GeoTIFF, default is NONE.

If executing a production workflow, the Compression method parameter from Set Image Path or Add Orthophoto is used, and this parameter is not editable.

CompressMethod
Export Directory

Set the storage path of the result image.

If executing a production workflow, the Processing path parameter from Set Image Path or Add Orthophoto is used, and this parameter is not editable.

File
Add Results to Map Window

This parameter is available only when the function is launched from the Satellite Image Processing tab -> DOM Data Production group -> True Color Output.

Checked by default, meaning the result data will be added to the map window for display after successful execution of the function.

Boolean
Create Image Pyramid

Checked by default. It can build pyramids for image data based on the specified resampling method, thereby improving the zoom display rendering and performance of the image.

If executing a production workflow, the Create Image Pyramid parameter from Set Image Path or Add Orthophoto is used, and this parameter is not displayed.

Boolean
Resampling Method

Available when Create Image Pyramid is checked. Default is Average. For more method introductions, please refer to Resampling Method.

If executing a production workflow, the Resampling Method parameter from Set Image Path or Add Orthophoto is used, and this parameter is not displayed.

PyramidResampleType
Asynchronously Create Statistics

When browsing the image, the layer will be stretched based on the statistics information. If the image does not have statistics information, the image will be displayed according to the default stretch method, and 8-bit data will not be stretched. Checked by default, meaning statistics will be created for the image in the background without affecting the workflow execution. If unchecked, statistics will be created simultaneously when executing this tool, which may consume time.

If executing a production workflow, the Asynchronously Create Statistics parameter from Set Image Path or Add Orthophoto is used, and this parameter is not displayed.

Boolean

Output Result

  • Output the stretched and image-enhanced image data to the local folder.
  • Based on the output image data, automatically create a true color image mosaic dataset in the OrthoData datasource.

Related Topics

Image Fusion

Image Color Balancing

Image Mosaic