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 3651 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 3665 of file processor.h.

03666                 {
03667                         return "Ramp processor -- Fits a least-squares plane "
03668                                    "to the picture, and subtracts the plane from "
03669                                    "the picture.  A wedge-shaped overall density "
03670                                    "profile can thus be removed from the picture.";
03671                 }

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 3656 of file processor.h.

References NAME.

Referenced by process_inplace().

03657                 {
03658                         return NAME;
03659                 }

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

Definition at line 3660 of file processor.h.

03661                 {
03662                         return new RampProcessor();
03663                 }

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 7830 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().

07831 {
07832         if (!image) {
07833                 return;
07834         }
07835 
07836         int nz = image->get_zsize();
07837         if (nz > 1) {
07838                 LOGERR("%s Processor doesn't support 3D model", get_name().c_str());
07839                 throw ImageDimensionException("3D model not supported");
07840         }
07841 
07842         int nsam = image->get_xsize();
07843         int nrow = image->get_ysize();
07844         int n1 = nsam / 2;
07845         double sx1 = double(n1)*double(nsam+1);
07846         if ( nsam % 2 == 1 )
07847                 sx1 += 1 + n1;
07848         sx1 *= nrow;
07849         int n2 = nrow / 2;
07850         double sx2 = double(n2)*double(nrow+1);
07851         if ( nrow % 2 == 1 )
07852                 sx2 += 1 + n2;
07853         sx2 *= nsam;
07854         float *data = image->get_data();
07855         float *row = NULL; // handy pointer for values in a specific row of the data
07856         // statistical sums
07857         double syx1 = 0, syx2 = 0, sy = 0, sx1q = 0, sx2q = 0, syq = 0;
07858         for (int j=1; j <= nrow; j++) {
07859                 row = data + (j-1)*nsam - 1; // "-1" so that we can start counting at 1
07860                 for (int i=1; i<=nsam; i++) {
07861                         syx1 += row[i]*i;
07862                         syx2 += row[i]*j;
07863                         sy += row[i];
07864                         sx1q += i*i;
07865                         sx2q += j*j;
07866                         syq += row[i]*double(row[i]);
07867                 }
07868         }
07869         // least-squares
07870         float dn = float(nsam)*float(nrow);
07871         double qyx1 = syx1 - sx1*sy / dn;
07872         double qyx2 = syx2 - sx2*sy / dn;
07873         double qx1x2 = 0.0;
07874         double qx1 = sx1q - sx1*sx1 / dn;
07875         double qx2 = sx2q - sx2*sx2 / dn;
07876         double qy = syq - sy*sy / dn;
07877         double c = qx1*qx2 - qx1x2*qx1x2;
07878         if ( c > FLT_EPSILON ) {
07879                 double b1 = (qyx1*qx2 - qyx2*qx1x2) / c;
07880                 double b2 = (qyx2*qx1 - qyx1*qx1x2) / c;
07881                 double a = (sy - b1*sx1 - b2*sx2) / dn;
07882                 double d = a + b1 + b2;
07883                 for (int i=1; i<=nrow; i++) {
07884                         qy = d;
07885                         row = data + (i-1)*nsam - 1;
07886                         for (int k=1; k<=nsam; k++) {
07887                                 row[k] -= static_cast<float>(qy);
07888                                 qy += b1;
07889                         }
07890                         d += b2;
07891                 }
07892         } // image not altered if c is zero
07893 
07894         image->update();
07895 }


Member Data Documentation

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

Definition at line 3673 of file processor.h.

Referenced by get_name().


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