risk-methods {aws}

Compute risks characterizing the quality of smoothing results

Description

Methods function risk in package aws. For an given array u the following statistics are computed : Root Mean Squared Error RMSE <- sqrt(mean((y-u)^2)), Signal to Noise Ratio SNR <- 10*log(mean(u^2)/MSE,10), Peak Signal to Noise Ratio PSNR <- 10*log(max(u^2)/MSE,10), Mean Absolute Error MAE <- mean(abs(y-u)), Maximal Absolute Error MaxAE <- max(abs(y-u)), Universal Image Quality Index (UIQI) (Wang and Bovik (2002)).

Usage

  ## S4 method for signature 'array'
risk(y, u=0)
  ## S4 method for signature 'aws'
risk(y, u=0)
  ## S4 method for signature 'awssegment'
risk(y, u=0)
  ## S4 method for signature 'ICIsmooth'
risk(y, u=0)
  ## S4 method for signature 'kernsm'
risk(y, u=0)
  ## S4 method for signature 'numeric'
risk(y, u=0)

Arguments

y

object

u

array of dimension dim(y) or dim(extract(y,what="yhat")$y) or scalar value used in comparisons.

Methods

signature(y = "ANY")

The method extract and/or compute specified statistics from object of class

signature(y = "array")

Returns a list with components RMSE, SNR, PSNR, MAE, MaxAE, UIQI

signature(y = "aws")

Returns a list with components RMSE, SNR, PSNR, MAE, MaxAE, UIQI

signature(y = "awssegment")

Returns a list with components RMSE, SNR, PSNR, MAE, MaxAE, UIQI

signature(y = "ICIsmooth")

Returns a list with components RMSE, SNR, PSNR, MAE, MaxAE, UIQI

signature(y = "kernsm")

Returns a list with components RMSE, SNR, PSNR, MAE, MaxAE, UIQI

signature(y = "numeric")

Returns a list with components RMSE, SNR, PSNR, MAE, MaxAE, UIQI

Author(s)

Joerg Polzehl [e-mail]

References

V. Katkovnik, K. Egiazarian and J. Astola, Local Approximation Techniques in Signal And Image Processing, SPIE Society of Photo-Optical Instrumentation Engin., 2006, PM157

Z. Wang and A. C. Bovik, A universal image quality index, IEEE Signal Processing Letters, vol. 9, N3, pp. 81-84, 2002.