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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal">I have a general GIS query and am hoping I can get some insight from the community.<o:p></o:p></p>
<p class="MsoNormal">It relates to how we deal with pixels with no data in RGB Imagery. It seems to be typical to produce RGB imagery as 8bit with pixel values between 0 and 255, with either 0 or 255 being used as the NoDATA value. To me this is problematic,
as there can be valid pixels within your image with 0 or 255. To me the solution is to use 16bit Imagery and to assign the NoDATA value to any value outside of the 0 – 255 range.<o:p></o:p></p>
<p class="MsoNormal">I know in DEM’s its usual to use -9999 as your NoDATA value but my question is, Is there a standardised way to deal with NoDATA in RGB?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I welcome any comments and suggestions.<o:p></o:p></p>
<p class="MsoNormal">Regards & Thanks in advance,<o:p></o:p></p>
<p class="MsoNormal"><br>
Richard.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<span style="FONT-FAMILY: Arial, sans-serif; FONT-WEIGHT: bold; COLOR: #004d44"><br>
——</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; FONT-WEIGHT: bold; COLOR: #004d44">Richard McDonnell MSc GIS, FME Certified Professional</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #004d44"><i>FRM Data Management</i></span><br>
<br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #004d44">——</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; FONT-WEIGHT: bold; COLOR: #004d44">Oifig na nOibreacha Poiblí</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #004d44">Office of Public Works</span><br>
<br>
<span style="FONT-FAMILY: Arial, sans-serif; FONT-WEIGHT: bold; COLOR: #565148">Sráid Jonathan Swift, Baile Átha Troim, Co na Mí, C15 NX36
</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #565148">Jonathan Swift Street, Trim, Co Meath, C15 NX36</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #565148">——</span><br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #565148">M +353 87 688 5964 T +353 46 942 2409</span><br>
<a href="https://gov.ie/opw">https://gov.ie/opw</a><br>
<br>
<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #004d44">——<br>
To send me files larger than 30MB, please use the link below https://filetransfer.opw.ie/filedrop/richard.mcdonnell@opw.ie<br>
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<span style="FONT-FAMILY: Arial, sans-serif; COLOR: #004d44">Email Disclaimer: https://www.gov.ie/en/organisation-information/439daf-email-disclaimer/
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