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EMAN::RampProcessor Class Reference

Ramp processor -- Fits a least-squares plane to the picture, and subtracts the plane from the picture. More...

#include <processor.h>

Inheritance diagram for EMAN::RampProcessor:

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Collaboration diagram for EMAN::RampProcessor:

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List of all members.

Public Member Functions

void process_inplace (EMData *image)
 To process an image in-place.
string get_name () const
 Get the processor's name.
string get_desc () const
 Get the descrition of this specific processor.

Static Public Member Functions

static ProcessorNEW ()

Static Public Attributes

static const string NAME = "filter.ramp"

Detailed Description

Ramp processor -- Fits a least-squares plane to the picture, and subtracts the plane from the picture.

A wedge-shaped overall density profile can thus be removed from the picture.

Definition at line 3726 of file processor.h.


Member Function Documentation

string EMAN::RampProcessor::get_desc  )  const [inline, virtual]
 

Get the descrition of this specific processor.

This function must be overwritten by a subclass.

Returns:
The description of this processor.

Implements EMAN::Processor.

Definition at line 3740 of file processor.h.

03741                 {
03742                         return "Ramp processor -- Fits a least-squares plane "
03743                                    "to the picture, and subtracts the plane from "
03744                                    "the picture.  A wedge-shaped overall density "
03745                                    "profile can thus be removed from the picture.";
03746                 }

string EMAN::RampProcessor::get_name  )  const [inline, virtual]
 

Get the processor's name.

Each processor is identified by a unique name.

Returns:
The processor's name.

Implements EMAN::Processor.

Definition at line 3731 of file processor.h.

References NAME.

Referenced by process_inplace().

03732                 {
03733                         return NAME;
03734                 }

static Processor* EMAN::RampProcessor::NEW  )  [inline, static]
 

Definition at line 3735 of file processor.h.

03736                 {
03737                         return new RampProcessor();
03738                 }

void RampProcessor::process_inplace EMData image  )  [virtual]
 

To process an image in-place.

For those processors which can only be processed out-of-place, override this function to just print out some error message to remind user call the out-of-place version.

Parameters:
image The image to be processed.

Implements EMAN::Processor.

Definition at line 7863 of file processor.cpp.

References EMAN::EMData::get_data(), get_name(), EMAN::EMData::get_xsize(), EMAN::EMData::get_ysize(), EMAN::EMData::get_zsize(), ImageDimensionException, LOGERR, and EMAN::EMData::update().

07864 {
07865         if (!image) {
07866                 return;
07867         }
07868 
07869         int nz = image->get_zsize();
07870         if (nz > 1) {
07871                 LOGERR("%s Processor doesn't support 3D model", get_name().c_str());
07872                 throw ImageDimensionException("3D model not supported");
07873         }
07874 
07875         int nsam = image->get_xsize();
07876         int nrow = image->get_ysize();
07877         int n1 = nsam / 2;
07878         double sx1 = double(n1)*double(nsam+1);
07879         if ( nsam % 2 == 1 )
07880                 sx1 += 1 + n1;
07881         sx1 *= nrow;
07882         int n2 = nrow / 2;
07883         double sx2 = double(n2)*double(nrow+1);
07884         if ( nrow % 2 == 1 )
07885                 sx2 += 1 + n2;
07886         sx2 *= nsam;
07887         float *data = image->get_data();
07888         float *row = NULL; // handy pointer for values in a specific row of the data
07889         // statistical sums
07890         double syx1 = 0, syx2 = 0, sy = 0, sx1q = 0, sx2q = 0, syq = 0;
07891         for (int j=1; j <= nrow; j++) {
07892                 row = data + (j-1)*nsam - 1; // "-1" so that we can start counting at 1
07893                 for (int i=1; i<=nsam; i++) {
07894                         syx1 += row[i]*i;
07895                         syx2 += row[i]*j;
07896                         sy += row[i];
07897                         sx1q += i*i;
07898                         sx2q += j*j;
07899                         syq += row[i]*double(row[i]);
07900                 }
07901         }
07902         // least-squares
07903         float dn = float(nsam)*float(nrow);
07904         double qyx1 = syx1 - sx1*sy / dn;
07905         double qyx2 = syx2 - sx2*sy / dn;
07906         double qx1x2 = 0.0;
07907         double qx1 = sx1q - sx1*sx1 / dn;
07908         double qx2 = sx2q - sx2*sx2 / dn;
07909         double qy = syq - sy*sy / dn;
07910         double c = qx1*qx2 - qx1x2*qx1x2;
07911         if ( c > FLT_EPSILON ) {
07912                 double b1 = (qyx1*qx2 - qyx2*qx1x2) / c;
07913                 double b2 = (qyx2*qx1 - qyx1*qx1x2) / c;
07914                 double a = (sy - b1*sx1 - b2*sx2) / dn;
07915                 double d = a + b1 + b2;
07916                 for (int i=1; i<=nrow; i++) {
07917                         qy = d;
07918                         row = data + (i-1)*nsam - 1;
07919                         for (int k=1; k<=nsam; k++) {
07920                                 row[k] -= static_cast<float>(qy);
07921                                 qy += b1;
07922                         }
07923                         d += b2;
07924                 }
07925         } // image not altered if c is zero
07926 
07927         image->update();
07928 }


Member Data Documentation

const string RampProcessor::NAME = "filter.ramp" [static]
 

Definition at line 3748 of file processor.h.

Referenced by get_name().


The documentation for this class was generated from the following files:
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