MASUDA Yuta > Cv-0.28 > Cv::More

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Module Version: 0.28   Source   Latest Release: Cv-0.29

NAME ^

Cv::More - A little more easy to using Cv in Perl.

SYNOPSIS ^

 use Cv::More qw(cs);

DESCRIPTION ^

Cv::More is a package to organize some of the experimental features from Cv. I believe it will be easier to extend the Cv. Cv::More is what separated the part of the Cv. So, it is enabled by default. Please make a explicit if you do not use.

 use Cv;              # enabled Cv::More
 use Cv -nomore;          # disabled Cv::More

Added or Extended Method

Cv::Arr - Using Perl Array

FitEllipse2()
 my $box2d = Cv->FitEllipse2($points);

The return value is CvBox2D. If you specify cs, and called in listcontext, the following elements will be expanded.

 use Cv::More qw(cs);
 my ($center, $size, $angle) = Cv->FitEllipse2($points);

The following example shows how to draw a list of points FitEllipse2().

 my $img = Cv::Image->new([250, 250], CV_8UC3)->fill(cvScalarAll(255));
 $img->origin(1);
 my @pts = (map { [ map { $_ / 4 + rand $_ / 2 } @{$img->size} ] } 1 .. 20);
 $img->circle($_, 3, &color, 1, CV_AA) for @pts;
 my $box = Cv->fitEllipse(\@pts);
 $img->polyLine([[Cv->boxPoints($box)]], -1, &color, 1, CV_AA);
 $img->ellipseBox($box, &color, 1, CV_AA);
 $img->show("FitEllipse2");
 Cv->waitKey;
 sub color { [ map { rand 255 } 1 .. 3 ] }
FitLine()

FitLine() has the following two methods call.

 my $line = Cv->FitLine($points, $dist_type, $param, $reps, $aeps);     # (1)
 Cv->FitLine($points, $dist_type, $param, $reps, $aeps, my $line);      # (2)

Can omit the parameters other than $points. $points is a list of points in two-or three-dimensional. The return value is determined by the number of dimensions of $points.

 my $points2d = [ [$x1, $y1], [$x2, $y2], ... ];
 my ($vx, $vy, $x0, $y0) = Cv->FitLine($points2d, ...);
 my $points3d = [ [$x1, $y1, $z1], [$x2, $y2, $z2], ... ];
 my ($vx, $vy, $vz, $x0, $y0, $z0) = Cv->FitLine($points3d, ...);

The following examples, draw a straight line fit to a collection of some points.

 my @pts = ([ 50, 50 ], [ 100, 120 ], [ 150, 150 ], [ 200, 150 ]);
 my ($vx, $vy, $x0, $y0) = Cv->fitLine(\@pts); 
 $img->line((map { [ $_, $vy / $vx * ($_ - $x0) + $y0 ] } 20, 230),
                        cvScalarAll(200), 3, CV_AA);
MinAreaRect2()
 my $box2d = Cv->MinAreaRect2($points);
 my ($center, $size, $angle) = Cv->MinAreaRect2($points);

The return value is CvBox2D, means the smallest rectangle enclosing a list of points.

 for ([ [ Cv->fitEllipse(\@pts)  ], [ 200, 200, 200 ] ],
      [ [ Cv->minAreaRect(\@pts) ], [ 100, 100, 255 ] ]) {
   $img->polyLine([[Cv->boxPoints($_->[0])]], -1, $_->[1], 1, CV_AA);
   $img->ellipseBox($_->[0], $_->[1], 1, CV_AA);
 }

To Cv-0.15, used the memory storage same as the interface of C language. But, Cv-0.16 and later versions do not use memory storage.

MinEnclosingCircle()
 my $circle = Cv->MinEnclosingCircle($points);                          # (1)
 my ($center, $radius) = Cv->MinEnclosingCircle($points);               # (1')
 Cv->MinEnclosingCircle($points, my $center, my $radius);               # (2)

The return value is the coordinates of the center $center and the radius of the circle $radius.

The following example drawn fitEllipse2(), minEnclosingCircle() and minAreaRect2() using a same list of points.

 my $rectangle = Cv->minAreaRect2(\@pts);
 my $ellipse = Cv->fitEllipse2(\@pts);
 my ($center, $radius) = Cv->minEnclosingCircle(\@pts);
 my $circle = [ $center, [ ($radius * 2) x 2 ], 0 ];
 for ([ $rectangle, [ 200, 200, 200 ] ],
      # [ $ellipse,   [ 200, 200, 200 ] ],
      [ $circle,    [ 100, 100, 255 ] ]) {
   $img->polyLine([[Cv->boxPoints($_->[0])]], -1, $_->[1], 1, CV_AA);
   $img->ellipseBox($_->[0], $_->[1], 1, CV_AA);
 }
BoundingRect()
 my $rect = Cv->BoundingRect($points)
 my ($x, $y, $width, $height) = Cv->BoundingRect($points)

Returns the minimal up-right bounding rectangle for the specified point set.The return value is CvRect. By converting to CvBox2D from CvRect as follows, and usability of BoxPoints EllipseBox better.

 my $box2d = [ [ $x + $width / 2, $y + $height / 2 ], [ $width, $height ], 0 ];
ContourArea()
 my $s = Cv->ContourArea($points)
 my $s = Cv->ContourArea($points, $slice)

The function computes the contour area. In the following example, area $s is the (100x100) horizontal x vertical.

 my @pts = ([100, 100], [100, 200], [200, 200], [200, 100]);
 my $s = Cv->contourArea(\@pts);
Transform()
 my $dst = Cv->Transform([ $pt1, $pt2, ... ], $transmat);               # (1)
 my @dst = Cv->Transform([ $pt1, $pt2, ... ], $transmat);               # (1')
 Cv->Transform([ $pt1, $pt2, ... ], my $dst, $transmat);                # (2)

 my @points = ( [$x1, $y1], [$x2, $y2], ... );
 my $arr = Cv::Mat->new([], CV_32FC2, @points);
 my $dst = $arr->Transform($transmat);                                  # (3)
 $arr->Transform(my $dst, $transmat);                                   # (4)

 my $dst = $arr->WarpAffine($transmat);                                 # (5)
 $arr->warpTransform(my $dst, $transmat);                               # (6)
Affine()

This method performs a rotation and contraction for images and matrix. Implementation is a wrapper for GetQuadrangleSubPix().

  my $mapMatrix = [ [ $A11, $A12, $b1 ],
                    [ $A21, $A22, $b2 ] ];
  my $dst = $src->Affine($mapMatrix);

This function makes it easy effort to make the transformation matrix. In addition, can also write the same in the following.

  $src->GetQuadrangleSubPix(
          Cv::Mat->new([], &Cv::CV_32FC1,
                       [ $A11, $A12, $b1 ],
                       [ $A21, $A22, $b2 ],
                       ));
new()
m_new()

Object of the matrix and the image in OpenCV is made by specifying the type and element size. m_new() is a method to redefine the new() so as to provide the value of each element. If specify an empty arrayref [] to the size of the matrix, the size of the matrix is the number of elements.

 my $mat = Cv::Mat->new([], $type, $elements);

The following is an example of a matrix camera. The size of matrix is 3x3, the element type is CV_32FC1.

 my $mat = Cv::Mat->new([ ], CV_32FC1,
    [ $fx,   0, $cx ],
    [   0, $fy, $cy ],
    [   0,   0,   1 ],
    );
Set()
m_set()
 $mat->Set($index, $value);

m_set() extends the <Set()> to make it possible to collectively set the element. As follows, $index is an array reference.

 $mat = Cv::Mat->new([ 2, 2 ], CV_32FC2);
 $value = [ 100, 100 ];

If any part of the index is omitted, 0 is supplemented.

 $mat->m_set([@$index, 0], $value);

In the case where $value is given as a list, the value of the element is set as follows in order from $index.

 $mat->m_set([@$index, $_], $value->[$_]) for 0 .. $#{$value};

For example,

 $mat->Set([ 0, 1 ], $value);
 # (1) set element [ 0, 1 ]
 # [
 #   [ [ 0, 0 ], [ 100, 100 ] ],
 #   [ [ 0, 0 ], [   0,   0 ] ],
 # ]
 
 $mat->Set([ 1 ], $value);
 # (2) set element [ 0, 1 ]
 # [
 #   [ [   0,   0 ], [   0,   0 ] ],
 #   [ [ 100, 100 ], [   0,   0 ] ],
 # ]
 
 $mat->Set([ 1 ], [ ($value) x 2 ]);
 # (2)' set element [ 0, 1 ], [ 1, 1 ]
 # [
 #   [ [   0,   0 ], [   0,   0 ] ],
 #   [ [ 100, 100 ], [ 100, 100 ] ],
 # ]
 
 $mat->Set([], $value);
 # (3) set element [ 0, 0 ]
 # [
 #   [ [ 100, 100 ], [   0,   0 ] ],
 #   [ [   0,   0 ], [   0,   0 ] ],
 # ]
 
 $mat->Set([], [ [ $value ], [ ($value) x 2 ] ]);
 # (3)' set element [ 0, 0 ], [ 0, 1 ], [ 1, 1 ]
 # [
 #   [ [ 100, 100 ], [ 100, 100 ] ],
 #   [ [   0,   0 ], [ 100, 100 ] ],
 # ]
ToArray()
 my @array = $arr->ToArray();                                           # (1)
 my @array = $arr->ToArray($slice);                                     # (2)

Converted into array of points from sequence or matrix (1xN, Nx1). To be able to convert the matrix, this method has been extended cvCvtSeqToArray() to convert the sequence. So can specify a range $slice give. This range can be represented by array reference [$ start, $ end] or cvSlice(). When you omit the range will convert all of the elements.

 $arr->ToArray(\my @array);
 $arr->ToArray(\my @attay, $slice);

It is useful if can use negative index like an array of Perl, which can not be.

 my @array = $arr->ToArray([ -1, 1 ]); # cannot use
 my @array = $arr->ToArray([ 1, -1 ]); # cannot use

Other Method

GetBuildInformation()
  my $info = Cv->GetBuildInformation()
  my %info = Cv->GetBuildInformation()

Build-time information can be retrieved from OpenCV 2.4.0. If the scalar context, returns the return value of cv::getBuildInformation(). If the list context, it returns the following results.

  'OpenCV modules' => {
        'Disabled by dependency' => '-',
        'Unavailable' => 'androidcamera java ocl',
        'Disabled' => 'world',
        'To be built' => 'core imgproc flann highgui features2d calib3d ml video objdetect contrib nonfree photo legacy gpu python stitching ts videostab'
  },
  'Version control' => 'commit:6484732',
  'Linker flags (Debug)' => {
        'Precompiled headers' => 'YES'
  },
  ...

t is used in the C <HasModule()>. In order to check the module available in OpenCV.

HasModule()
 my $hasCore = Cv->HasModule('core');

This method returns what has been built to enable any module in OpenCV.

SEE ALSO ^

Cv

LICENCE ^

MASUDA Yuta <yuta.cpan@gmail.com>

Copyright (c) 2012, 2013 by MASUDA Yuta.

All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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