REMOVING THE BLACK BACKGROUND COLOUR FROM LANDSAT IMAGERY

Mosaicking Landsat images is a pivotal step in creating comprehensive satellite composites. However, the resulting amalgamation often introduces an unwanted companion - a persistent black background. This seemingly insurmountable challenge can hinder accurate analysis. In this article, we will explore advanced techniques to deftly erase this hindrance, enabling researchers and analysts to unlock the full potential of Landsat imagery for a wide range of applications.

Below is a step by step procedure on how to remove the black background colour using ArcMap desktop GIS software

1.      LOADING BANDS

Load your dataset you want to work on by using the add data tab in the ArcMap.  In this case will use raster dataset.

2.      MOSAICKING(MERGING) LAYERS

Mosaicking is a fundamental process in remote sensing that involves stitching together multiple individual satellite images to create a seamless composite of a larger geographic area. This technique is essential for obtaining a comprehensive view of Earth's surface, as individual satellite images often cover limited spatial extents. To mosaic images using ArcMap the steps below are followed:

ü  After loading your data you are now ready to do mosaicking

ü  Rightclick on one of the data and click on properties

ü  Click on the source tab. This provides more information about your dataset

ü  Confirm the cell size, Pixel type and the pixel depth

ü  In the Arc Toolbox, click Data Management Tools >then Raster> Raster Dataset> Double click on Mosaic To New Raster. It will display the table below.

ü 

ü  Fill the required details; i.e on Input Rasters: images to be merged, Output Location: Specify the location you want to save your work, Raster Dataset Name With Extension: Specify the name of the output and include the extension eg in my case  is used .tif, Pixel Type,Cellsize and Number of Bands fill properties of your dataset.

The results will be a merged image which contain a black background such as the image below.

For better analysis this background needs to be removed.

3.      REMOVING THE BLACK BACKGROUND

·         Right click on the layer> click on properties

·         Click on the symbology tab and then click Stretched.

·         To remove the background colour tick on the Display Background Value check  box.

As we wrap up, remember that practice and experimentation are key. Embrace the tools and techniques, and let your creativity soar. With each successful endeavor, you're one step closer to harnessing the full potential of Landsat imagery for a myriad of applications. Happy mapping!