NAME

Panotools::Photos - Photo sets

SYNOPSIS

Query sets of photos

DESCRIPTION

A collection of photos has possibilities, it could be one or more panoramas or a bracketed set. This module provides some methods for describing groups of photos based on available metadata

USAGE

Create a new object like so:

            

              
              
my $photos = new Panotools::Photos;
            
          

Alternatively supply some filenames:

            

              
              
my $photos = new Panotools::Photos ('DSC_0001.JPG', 'DSC_0002.JPG');
            
          

Paths

Add to or get the list of image filenames:

            

              
              
$photos->Paths ('DSC_0003.JPG', 'DSC_0004.JPG');
my @paths = $photos->Paths;
            
          

Stub

Construct a stub filename from the names of the first and last images in the list.

            

              
              
my $stub = $photos->Stub;
            
          

e.g. DSC_0001.JPG DSC_0002.JPG DSC_0003.JPG -> DSC_0001-DSC_0003

Bracketed

Query to discover if this is a likely bracketed set. i.e. is the total number of photos divisible by the number of different exposures:

            

              
              
&do_stuff if ($photos->Bracketed);
            
          

Layered

Query to discover if this is a layered set, i.e. there is a large exposure difference in the set, but it isn't bracketed.

            

              
              
&do_stuff if ($photos->Layered);
            
          

By default the threshold is 4, e.g. exposures varying between 2 and 1/2 seconds indicate layers. Vary this threshold like so:

            

              
              
&do_stuff if ($photos->Layered (2));
            
          

Speeds

Get a list of exposure times sorted with longest exposure first

            

              
              
@speeds = @{$photos->Speeds};
            
          

SplitInterval

Given a set of photos, split it into a one or more sets by looking at the variation of time interval between shots. e.g. typically the interval between shots in a panorama varies by less than 15 seconds. A variation greater than that indicates the start of the next panorama:

            

              
              
my @sets = $photos->SplitInterval (15);
            
          

Sets with an average interval greater than 4x this variation are not considered panoramas at all and discarded.

AverageInterval

Get the average time between shots:

            

              
              
$average = $photos->AverageInterval;
            
          

FOV FocalLength Rotation

Get the Angle of View in degrees of the first photo:

            

              
              
$photos->FOV;
            
          

..or any other photo (-1 is last):

            

              
              
$photos->FOV (123);
            
          

Returns undef if the FOV can't be calculated.

Eev

Get an EV value for a photo, this will be guessed from partial EXIF data:

            

              
              
$photos->Eev ($index);
            
          

AverageRGB

Find the mean average colour balance for all photos:

            

              
              
($red, $green, $blue) = $photos->AverageRGB;