jpegR: Produces small jpegs of satellite imagery

In Bartesto/BARTpkg: Utility Functions for Working with Remote Sensing Data

Description

This function makes small jpeg images centred on and showing site locations. This step is part of the cloud quality check process prior to extracting satellite bands or indices. Although designed to help the QA process the jpegs can be useful for quickly checking many image dates for change (e.g. fires, vegetation removal, etc). When run the function:

1. obtains a list of imagery folders to access. Can be from one of 2 sources. Either from auto cloud QA'd output (fmaskcheckR) or from all available imagery output (checkR). These functions are called internally

2. obtains individual site shps from QAshapes folder

3. creates a small jpeg of the individual sites for each image date as per step 1 for the purposes of visual QA

4. jpegs are based on band combination from user input and buffered by desired distance

5. all outputs are placed in appropriately named folders per site in the working directory

Usage

jpegR(wkdir, imdir, shp, shp.ID, buff, red, green, blue, fmask)

Arguments

wkdir	character string of the working directory where your original shape file is located
imdir	character string of the directory where imagery is located to path/row level
shp	character string of the name of the shape file (no extension)
shp.ID	character string of the name of the field in the attribute table of the shape file that contains the unique entries (e.g.site numbers)
buff	numeric representing how much to buffer out the site in metres. It is a way to control zoom level for jpegs
red	numeric representing what satellite band to display in the red channel
green	numeric representing what satellite band to display in the green channel
blue	numeric representing what satellite band to display in the blue channel
fmask	character string 'y' or 'n' representing whether fmask products exist in each of the image date folders. Suggest 'n' as majority of our Landsat archive has not been processed by fmask

Value

creates named folders, based on site location and dates of images processed, containing small jpeg images for visual QA

Author(s)

Bart Huntley, [e-mail]

Examples

## Not run: 
jpegR("../wkdir", "../imdir", "plot_locations", "Plot_ID", 2000, 5, 4, 2, 'n')

## End(Not run)

Bartesto/BARTpkg documentation built on May 5, 2019, 10:28 a.m.