A friend came to me asking if I could help him making crawling through his thousands of camera images a little easier. His camera named his pictures in a confusing manner I guess so I came up with this. This uses the EXIF data of the images to rename your images in a date/time format. It also supports sequences, which are pictures taken in rapid succession. This only does png/jpg's and the extension part is a bit sloppy (is jpeg a thing still?).

As I know images are important to people, if you find any bugs, please immediately report them to me.
Thanks!

#!/usr/bin/perl

use Image::ExifTool qw(:Public);
use File::Copy qw(move);
use warnings; use strict;

## This will rename all your jpg/png files in a folder
## in a YYYY-MM-DD_HH-MM-SS_SEQ# format based off of EXIF data
## The folder used is specified on the command line; if a location
## is not specified, it will default to your home directory

## Examples:
## perl exif_name.pl /home/dan/pictures/2005
## perl exif_name.pl
## perl exif_name.pl /usr/share/pictures/

## The renamed files are placed in a folder called OUTPUT
## which will be located inside the folder specified, or home default.

my $d = shift || $ENV{"HOME"};
if ($d =~ /\/$/) { chop $d; }

#Read directory files into an array
opendir D, "$d" || die "Can't open directory $d: $!\n";
    my @list = readdir(D);
closedir(D);

#Store image files in an array; skip other files and hidden files
my @files;
foreach my $file (@list) {
    next if $file =~ /^\./;
    next if $file !~ /[jpg|png]$/gi;
    print "Adding $file\n";
    push @files, $file;
}

#If we didn't find any images, die
if (scalar @files < 1) { die "No suitable images found!\n"; }

#If we can't make the output folder, die
#Skip check if output exists already
if (! -e "$d/OUTPUT/") {
    unless (mkdir "$d/OUTPUT") {
        die "Unable to create output directory, make sure you have
             permissions";
    }
}

#For each image, we grab the date/time and sequence number
#as well as the extension. If no time can be grabbed, it is
#assumed no EXIF is present and we will skip that file.
my $count = 0;
foreach my $file (@files) {
    my $exifTool = new Image::ExifTool;
    my $filename;

    $exifTool->ExtractInfo("$d/$file");
    my $time = $exifTool->GetValue('DateTimeOriginal');
    my $seq  = $exifTool->GetValue('SequenceNumber');
    my $ext = substr $file, -3;

    next if !$time;

    if ($time =~ /(\d+):(\d+):(\d+)\s(\d+):(\d+):(\d+)/) {
        my ($year, $month, $day, $hour, $minute, $second)
        =  ($1, $2, $3, $4, $5, $6);

        $filename = "$year-$month-$day\_$hour-$minute-$second";

        if ($seq) {
            $filename .= "_$seq.$ext";
        } else {
            $filename .= ".$ext";
        }

        print "$d/OUTPUT/$filename\n";

        if (-e "$d/OUTPUT/$filename") {
            my $choice = 0;
            print "A file with this name exists already. Proceeding will" .
                  " overwrite the existing file.\n";

            while ($choice !~ /[a|s|o]/) {
                print "[a]bort, [s]kip, [o]verwrite: ";
                $choice = <STDIN>;
                chomp $choice;
            }

            if ($choice eq "a") {
                die "Aborted by user\n";
            } elsif ($choice eq "s") {
                print "Skipped $file\n";
                next;
            } else {
                print "Overwriting $file\n";
            }
        }

        move "$d/$file", "$d/OUTPUT/$filename";

        $count++;
    }
}

print "Finished: $count images stored\n";