ee_extra.QA.metrics.ERGAS#

class ee_extra.QA.metrics.ERGAS(original: Image, modified: Image, reproject: bool = True, **kwargs: Any)[source]#

Calculate image-wise Dimensionless Global Relative Error of Synthesis (ERGAS) between an original and modified image with the same bands. A value of 0 represents no error. ERGAS results are weighted by the change in spatial resolution, identified from the nominalScale of the images.

Parameters:

  • original – The original image to use as a reference.

  • modified – The modified image to compare to the original.

  • reproject – If true, the original image will be reprojected to the modified image scale before calculation.

  • kwargs – Additional keyword arguments passed to ee.Image.reduceRegion.

Returns:

A dictionary with band names as keys and ERGAS values as values.

References

Vaiopoulos, A. D. (2011). Developing Matlab scripts for image analysis

and quality assessment. Earth Resources and Environmental Remote Sensing/GIS Applications II. https://doi.org/10.1117/12.897806

Examples

>>> from ee_extra.QA import metrics
>>> bands = ["B4", "B3", "B2"]
>>> img1 = ee.Image("COPERNICUS/S2_SR/20210703T170849_20210703T171938_T14SPG").select(bands)
>>> img2 = ee.Image("COPERNICUS/S2_SR/20210708T170851_20210708T171925_T14SPG").select(bands)
>>> metrics.ERGAS(img1, img2, h=10, l=10, bestEffort=True).getInfo()
3774.9270912567363
__init__()#

Methods

__init__()