Changes between Version 12 and Version 13 of CreateLandsatMosaic


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Timestamp:
Apr 28, 2014, 7:11:06 AM (8 years ago)
Author:
andreasplesch
Comment:

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  • CreateLandsatMosaic

    v12 v13  
    1 == How to generate efficiently a large Landsat7 mosaic ==
     1[[TOC]]
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     4= How to generate efficiently a large Landsat7 mosaic =
     5
     6== Introduction ==
    27
    38A common task may be to stitch together the freely available Landsat7 scenes to create a much larger image. For example, we would like to have a image covering a complete U.S. state such as California. Often a resolution of about 250m per pixel may suffice and then other sources such as MODIS become preferable. If higher resolutions are required it becomes necessary to deal with the creation of a large mosaic from many tiles which requires some efficiency in data processing. The goal will be to have a large single file as output.
     
    17226) post-process with gimp: levels, color balance, color enhance
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    19 === Detailed steps ===
     24== Detailed steps ==
    2025
    2126=== get LS7 scenes ===
     
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    115120Gimp can deal with large tiffs pretty well. I found that enhancing the contrast per channel by restricting the channel input levels, then some global, careful color balancing followed by auto-color enhancement can bring out features of interest or help to produce an image which is better suited to the human eye. Gimp is also good for subsampling since it efficiently implements interpolation. For example, it may suffice to subsample from the original 30m resolution to 120m which cuts down file size by a factor of 16 but is still noticeably better than 250m MODIS resolution.
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     122
     123== Edits to this page ==
     124
     125[[RecentChanges(CreateLandsatMosaic)]]