GPT Cookbook: WriteImage


Creates an image file from an input source file.


Example 1  Simple Image

Example 2  Image with Color Palette

Example 3  Image with Color Palette and Land Mask






Example 1    Simple Image


This creates a simple image with a default color palette applied with range based on data statistics.


Command Line Entry 

gpt WriteImage.xml -p WriteImageEx01.par -Ssource=V20172132017243.L3m_MO_SNPP_CHL_chlor_a_9km.nc -PfilePath=WriteImageEx01.png

File = WriteImage.xml 

<graph id="someGraphId">
  <version>1.0</version>
  <node id="someNodeId">
    <operator>WriteImage</operator>
    <sources>
      <source>${source}</source>
    </sources>
    <parameters>
      <sourceBandName>${sourceBandName}</sourceBandName>
      <filePath>${filePath}</filePath>
      <formatName>${formatName}</formatName>
      <level>${level}</level>
    </parameters>
  </node>
</graph>

File = WriteImageEx01.par 

sourceBandName=chlor_a
formatName=png
level=0



Example 2    Image with Color Palette


This creates an image with a color palette applied.


Command Line Entry 

gpt WriteImagePalette.xml -p WriteImageEx02.par -Phome=$HOME -Ssource=V20172132017243.L3m_MO_SNPP_CHL_chlor_a_9km.nc -PfilePath=WriteImageEx02.png

File = WriteImagePalette.xml 

<graph id="someGraphId">
  <version>1.0</version>
  <node id="someNodeId">
    <operator>WriteImage</operator>
    <sources>
      <source>${source}</source>
    </sources>
    <parameters>
      <sourceBandName>${sourceBandName}</sourceBandName>
      <filePath>${filePath}</filePath>
      <formatName>${formatName}</formatName>
      <cpdFilePath>${home}/${cpdFilePath}</cpdFilePath>
      <cpdAutoDistribute>${cpdAutoDistribute}</cpdAutoDistribute>
      <colourScaleMin>${colourScaleMin}</colourScaleMin>
      <colourScaleMax>${colourScaleMax}</colourScaleMax>
      <level>${level}</level>
      <scaleType>${scaleType}</scaleType>
    </parameters>
  </node>
</graph>

File = WriteImageEx02.par 

sourceBandName=chlor_a
formatName=png
cpdFilePath=.seadas/beam-ui/auxdata/color-palettes/universal_bluered.cpd
cpdAutoDistribute=false
colourScaleMin=0.01
colourScaleMax=20.0
level=0
scaleType=log



Example 3    Image with Color Palette and Land Mask


This is a very special case example. In the example use a separate land file in order to create a mask. The separate mask file must be the exact dimensions of the source file. Also the source file must not already contain masks.


Command Line Entry 

gpt WriteImageMask.xml -p WriteImageEx03.par -Phome=$HOME -Ssource=V20172132017243.L3m_MO_SNPP_CHL_chlor_a_9km.nc -PfilePath=WriteImageEx03.png

File = WriteImageMask.xml 

<graph id="someGraphId">
  <version>1.0</version>
  <node id="someNodeId">
    <operator>WriteImage</operator>
    <sources>
      <source>${source}</source>
    </sources>
    <parameters>
      <sourceBandName>${sourceBandName}</sourceBandName>
      <filePath>${filePath}</filePath>
      <formatName>${formatName}</formatName>
      <cpdFilePath>${home}/${cpdFilePath}</cpdFilePath>
      <cpdAutoDistribute>${cpdAutoDistribute}</cpdAutoDistribute>
      <colourScaleMin>${colourScaleMin}</colourScaleMin>
      <colourScaleMax>${colourScaleMax}</colourScaleMax>
      <level>${level}</level>
      <scaleType>${scaleType}</scaleType>

      <maskFilePath>${home}/${maskFilePath}</maskFilePath>
      <maskLayer>true</maskLayer>
      <imageMasks>
        <imageMask>
          <imageMaskSourceBandName>water_fraction</imageMaskSourceBandName>
          <imageMaskName>LandMask</imageMaskName>
          <imageMaskDescription>Land Mask</imageMaskDescription>
          <imageMaskExpression>water_fraction == 0</imageMaskExpression>
          <imageMaskColor>51,51,51</imageMaskColor>
          <imageMaskTransparency>0.0</imageMaskTransparency>
        </imageMask>
      </imageMasks>

    </parameters>
  </node>
</graph>

File = WriteImageEx03.par 

sourceBandName=chlor_a
formatName=png
cpdFilePath=.seadas/beam-ui/auxdata/color-palettes/universal_bluered.cpd
maskFilePath=Desktop/GptExamples/help/WriteImage/V20172132017243.L3m_LAND_9km.dim
cpdAutoDistribute=false
colourScaleMin=0.01
colourScaleMax=20.0
level=0
scaleType=log