Index: /trunk/doc/modules/ModulesSDRS.tex =================================================================== --- /trunk/doc/modules/ModulesSDRS.tex (revision 1448) +++ /trunk/doc/modules/ModulesSDRS.tex (revision 1449) @@ -1,3 +1,3 @@ -%%% $Id: ModulesSDRS.tex,v 1.10 2004-08-09 23:20:02 price Exp $ +%%% $Id: ModulesSDRS.tex,v 1.11 2004-08-10 01:56:47 price Exp $ \documentclass[panstarrs]{panstarrs} @@ -52,11 +52,15 @@ This document describes the Pan-STARRS Image Processing Pipeline (IPP) -image processing modules. The modules use the functionality \PS{} -Library (PSLib) perform more complex tasks. +image processing modules. The modules use the functionality of the +\PS{} Library (PSLib) to perform more complex tasks. They will +eventually be tied together, employing a script written in a +high-level language to form a ``processing stage''. Modules will be +constructed to support each of the required processing stages, and are +listed in this document according to the particular processing stage +for which they will primarily be used. In order to preserve name space, globally-visible structures and functions shall be prefixed with \code{pm}, for ``\PS{} Modules''. -Modules will be constructed to support each of the processing stages. \section{Phase 2} @@ -65,13 +69,4 @@ are removed from the detector images, in preparation for the combination of multiple images in Phase 4. - -The Phase 2 processing stage is composed of several modules which -perform the individual steps in the processing, each of which will act -upon a data element of the appropriate size. For example, the bias -subtraction module will act upon a detector ``readout'' -(\code{psReadout}). It will be the responsibility of the caller of -the Phase 2 processing modules (i.e., the Phase 2 processing stage, -which will likely be a script written in a high-level language such as -\tbd{Python}) to iterate over the components with which it is charged. The Phase 2 processing modules are: @@ -107,5 +102,5 @@ psReadout *pmSubtractBias(psReadout *in, void *fitSpec, const psList *overscans, pmOverscanAxis overscanAxis, const psStats *stat, - int nBin, psFit fit, const psReadout *bias); + int nBin, pmFit fit, const psReadout *bias); \end{verbatim} @@ -130,11 +125,15 @@ appropriate type (\code{psPolynomial1D} for \code{PM_FIT_POLYNOMIAL}, and \code{psSpline1D} for \code{PM_FIT_SPLINE}), and the overscan -shall be fit using the specified functional form. Upon return, the -\code{fitSpec} shall contain the coefficients of the overscan fit. +shall (after reduction of the vector and binning) be fit using the +specified functional form. Upon return, the \code{fitSpec} shall +contain the coefficients of the overscan fit. The prescan and/or overscan regions to be used are specified in -\code{overscans}, which is a linked list of subimages. If -\code{overscans} is non-\code{NULL} and \code{overscanAxis} is not -\code{PM_OVERSCAN_NONE}, then the function shall generate a warning. +\code{overscans}, which is a linked list of subimages. In cases where +\code{overscans} is \code{NULL} and \code{overscanAxis} is not +\code{PM_OVERSCAN_NONE}, or if \code{overscans} is non-\code{NULL} and +\code{overscanAxis} is \code{PM_OVERSCAN_NONE}, then the function +shall generate a warning, no overscan subtraction shall be performed, +and the function shall proceed to the full-frame bias subtraction. The \code{overscanAxis} specifies how the prescan/overscan subtraction @@ -151,11 +150,11 @@ If the \code{overscanAxis} is \code{PM_OVERSCAN_NONE}, then the -function shall not perform any overscan subtraction. If the -\code{overscanAxis} is \code{PM_OVERSCAN_ALL}, then all the overscan -regions shall be used to generate a single statistic (specified by -\code{stat}) which shall be subtracted from the entire image. A -warning shall be generated if the \code{overscanAxis} is -\code{PM_OVERSCAN_NONE} or \code{PM_OVERSCAN_ALL} and the \code{fit} -is not \code{PM_FIT_NONE}. +function shall not perform any overscan subtraction, but proceed to +the full-frame bias subtraction. If the \code{overscanAxis} is +\code{PM_OVERSCAN_ALL}, then all the overscan regions shall be used to +generate a single statistic (specified by \code{stat}) which shall be +subtracted from the entire image. A warning shall be generated if the +\code{overscanAxis} is \code{PM_OVERSCAN_NONE} or +\code{PM_OVERSCAN_ALL} and the \code{fit} is not \code{PM_FIT_NONE}. If the \code{overscanAxis} is \code{PM_OVERSCAN_ROWS} or @@ -175,11 +174,12 @@ \code{PS_STAT_ROBUST_MODE}. -If \code{nBin} is positive and less than the dimension -of the vector, then the vector shall subsequently be binned down into -\code{nBin} bins, again using the specified statistic (\code{stat}). +If \code{nBin} is positive and less than the dimension of the vector, +then the vector shall subsequently be binned into \code{nBin} bins, +again using the specified statistic (\code{stat}). + If the overscan is not defined for each row/column, then the function shall generate a warning and then interpolate using the provided -functional form if \code{fit} is not \code{PM_FIT_NONE}; -otherwise, the function shall generate an error. +functional form if \code{fit} is not \code{PM_FIT_NONE}; otherwise, +the function shall generate an error. Following any binning, the vector shall be fit by the functional form @@ -205,12 +205,11 @@ \subsection{Non-linearity} -We shall specify two functions to perform the non-linearity -correction, in order to implement the possible methods of specifying -the correction. +We here specify two functions to perform the non-linearity correction, +since either (or both) might be used to specify the correction. The first, \code{pmNonLinearityPolynomial} shall correct the input -image for non-linearity by applying the given polynomial, -\code{coeff}, to the flux of each pixel in the input image, \code{in}. -The API shall be the following: +image for non-linearity by replacing the flux in each pixel of the +input image, \code{in}, with the result of the specified polynomial, +\code{coeff}, acting on the flux. The API shall be the following: \begin{verbatim} @@ -239,9 +238,13 @@ If the particular value of a pixel is not found in the \code{inFlux} vector, the corresponding \code{outFlux} shall be calculated through -linear interpolation. +linear interpolation. If the value of a pixel is beyond the range of +values specified in the \code{inFlux} vector, then the function shall +generate a warning (at most one warning of this type per call, +preferably mentioning the number of pixels out of bounds). In the event that the \code{inFlux} vector does not contain two or -more entries (necessary for linear interpolation), then the function -shall generate a warning, and make no correction to any of the pixels. +more entries (being the lower limit required for linear +interpolation), then the function shall generate a warning, and make +no correction to any of the pixels. Both \code{pmNonLinearityPolynomial} and \code{pmNonLinearityLookup} @@ -270,6 +273,7 @@ in the input image with the value \code{PM_MASK_FLAT} (see \S\ref{sec:maskValues}). Negative pixels in the \code{flat} may be -set to zero so that they are treated identically to zeroes. And -pixels masked in the \code{flat} shall be masked in the \code{output}. +set to zero so that they are treated identically to zeroes. Any +pixels masked in the \code{flat} shall be masked with corresponding +values in the \code{output}. The function shall not normalize the \code{flat}; this responsibility @@ -283,6 +287,4 @@ \subsection{Masking} -The following modules mask various defects on an image. - \subsubsection{Mask values} \label{sec:maskValues} @@ -295,6 +297,5 @@ PM_MASK_BADCOL, ///< The pixel is a bad column PM_MASK_SAT, ///< The pixel is saturated - PM_MASK_FLAT, ///< The pixel is non-positive in the flat-field - PM_MASK_CR_MORPH ///< The pixel is determined to be a cosmic ray, from morphology + PM_MASK_FLAT ///< The pixel is non-positive in the flat-field } pmMaskValue; \end{verbatim}