Name
Image::Find::Loops - Find loops in an image.
Synopsis
Use new to create and analyze a new image, then print to visualize the loops detected, or loop to get the coordinates of points in each loop in sequential order.
Description
Find loops in an image.
The following sections describe the methods in each functional area of this module. For an alphabetic listing of all methods by name see Index.
Methods
Find loops in an image.
new($)
Find loops in an image represented as a string.
Parameter Description
1 $string String of blanks; non blanks; new lines defining the imageExample:
my $d = new (<<END);
11 11111111111 11111111111
1111 1 1 1 1
11 11 1111 1 111 1 1 1 1
11 11 11 11 1 1 1 1 1 1
11 11 11 11 1 1 1 1 1 1
1111 11111 1 1 1 1 1 1
11 1111 1 1 1 1111111111 1 1
1111 1 1 1 1111111111 1 1
11111 1 1 1 1 1 1
111111111111111111 1 1 1 1 1 1
11 1111111111 1 111 1 1 1 1
1 11111111 1 1 1 1
11111111111 1 1 1 1
111 11111111111 11111111111
END
ok nws($d->print) eq nws(<<END);
0 1 2 3 4 5 6 7
0123456789012345678901234567890123456789012345678901234567890123456789012345678
0
1 56 12345678901 23456789012
2 3478 8 2 1 3
3 12 90 1234 7 432 3 0 4
4 2 1 09 5 6 5 1 4 9 5
5 10 32 78 67 5 6 0 5 8 6
6 9854 63298 4 7 9 6 7 7
7 76 5410 3 8 8 7890123456 8
8 0123 2 9 7 0987654321 9
9 89 4 1 0 6 1 0 0
10 123412367 5678 0 1 5 2 9 1
11 0 45 09 9 234 3 8 2
12 9 654321 8 4 7 3
13 8765432107 7 5 6 4
14 98 65432109876 54321098765
Image: X = 79, Y = 15, Loops = 4
END
ok nws($d->printLoop(2)) eq nws(<<END);
1 2
678901234567890123
3 1111
4 22 1
5 22 22
6 22412
7 1334
8 3411
9 11 1
10 111111111 1111
11 1 22 22
12 1 111111
13 1111111122
14 21
Image: X = 79, Y = 15, Loop = 2
END
ok nws($d->printLoop(3)) eq nws(<<END);
3 4 5
012345678901234567890123456789
1 11111111111 11111111111
2 1 1 1 1
3 1 1 1 1
4 1 1 1 1
5 1 1 1 1
6 1 1 1 1
7 1 1222222221 1
8 1 1222222221 1
9 1 1 1 1
10 1 1 1 1
11 1 1 1 1
12 1 1 1 1
13 1 1 1 1
14 11111111111 11111111111
Image: X = 79, Y = 15, Loop = 3
END
ok nws($d->printLoop(4)) eq nws(<<END);
3 4
9012345678901
0
1
2
3 111
4 1 1
5 1 1
6 1 1
7 1 1
8 1 1
9 1 1
10 1 1
11 111
12
13
14
Image: X = 79, Y = 15, Loop = 4
ENDThis is a static method and so should be invoked as:
Image::Find::Loops::newnumberOfLoops($)
Number of loops in the image. The partitions and loops are numbered from 1.
Parameter Description
1 $i ImageExample:
is_deeply [$d->count, $d->x, $d->y, $d->numberOfLoops],
[239, 79, 15, 4];loop($$)
Return an array of arrays [x, y] of sequentially touching pixels describing the largest loop in the specified partition where the loops in an image are numbered from 1.
Parameter Description
1 $i Image
2 $partition PartitionExample:
is_deeply [grep{$_->[2] > 2} @{$d->loop(2)}],
[[15, 8, 3],
[15, 7, 3],
[15, 6, 4],
[14, 7, 3],
[16, 7, 4],printLoop($$)
Print a loop in the image numbering pixels with the estimated thickness of the loop.
Parameter Description
1 $i Image
2 $partition PartitionExample:
ok nws($d->printLoop(2)) eq nws(<<END);
1 2
678901234567890123
3 1111
4 22 1
5 22 22
6 22412
7 1334
8 3411
9 11 1
10 111111111 1111
11 1 22 22
12 1 111111
13 1111111122
14 21
Image: X = 79, Y = 15, Loop = 2
END
ok nws($d->printLoop(3)) eq nws(<<END);
3 4 5
012345678901234567890123456789
1 11111111111 11111111111
2 1 1 1 1
3 1 1 1 1
4 1 1 1 1
5 1 1 1 1
6 1 1 1 1
7 1 1222222221 1
8 1 1222222221 1
9 1 1 1 1
10 1 1 1 1
11 1 1 1 1
12 1 1 1 1
13 1 1 1 1
14 11111111111 11111111111
Image: X = 79, Y = 15, Loop = 3
END
ok nws($d->printLoop(4)) eq nws(<<END);
3 4
9012345678901
0
1
2
3 111
4 1 1
5 1 1
6 1 1
7 1 1
8 1 1
9 1 1
10 1 1
11 111
12
13
14
Image: X = 79, Y = 15, Loop = 4
ENDprint($)
Print the loops in an image sequentially numbering adjacent pixels in each loop from 0..9.
Parameter Description
1 $i ImageExample:
ok nws($d->print) eq nws(<<END);
0 1 2 3 4 5 6 7
0123456789012345678901234567890123456789012345678901234567890123456789012345678
0
1 56 12345678901 23456789012
2 3478 8 2 1 3
3 12 90 1234 7 432 3 0 4
4 2 1 09 5 6 5 1 4 9 5
5 10 32 78 67 5 6 0 5 8 6
6 9854 63298 4 7 9 6 7 7
7 76 5410 3 8 8 7890123456 8
8 0123 2 9 7 0987654321 9
9 89 4 1 0 6 1 0 0
10 123412367 5678 0 1 5 2 9 1
11 0 45 09 9 234 3 8 2
12 9 654321 8 4 7 3
13 8765432107 7 5 6 4
14 98 65432109876 54321098765
Image: X = 79, Y = 15, Loops = 4
ENDAttributes
Attributes of an image
bounds :lvalue
The bounds of each partition: [$x1, $y1, $x2, $y2].
count :lvalue
Number of points in the image.
image :lvalue
Image data points.
partitions :lvalue
Number of partitions in the image.
partitionLoop :lvalue
Loop for each partition.
x :lvalue
Image dimension in x.
y :lvalue
Image dimension in y.
Private Methods
fillPartition($$)
Remove any interior voids in a partition.
Parameter Description
1 $i Image
2 $partition Partitionclone($)
Clone an image.
Parameter Description
1 $i ImageExample:
is_deeply $d, $d->clone;clonePartition($$)
Clone a partition of an image.
Parameter Description
1 $i Image
2 $partition PartitionpartitionImage($$)
Partition the images into disjoint sets of connected points.
Parameter Description
1 $i Image
2 $small Minimum size of a partition - smaller partitions will be ignoredmapPartition($$$$)
Locate the pixels in the image that are connected to a pixel with a specified value.
Parameter Description
1 $i Image
2 $x X coordinate of first point in partition
3 $y Y coordinate of first point in partition
4 $small Delete partitions of fewer pixelsremoveInteriorOfPartition($$)
Remove the interior of a partition to leave the exterior loop.
Parameter Description
1 $I Image
2 $partition PartitionfindLongestLoop($$)
Find the longest loop in a partition.
Parameter Description
1 $I Image
2 $partition PartitionsearchArea($$$$)
Return the pixels to search from around a given pixel.
Parameter Description
1 $i Image
2 $partition Partition
3 $x X coordinate of center of search
4 $y Y coordinate of center of search.widthOfLoop($$)
Find the (estimated) width of the loop at each point.
Parameter Description
1 $I Image
2 $partition PartitionIndex
1 bounds
2 clone
4 count
7 image
8 loop
10 new
14 partitions
15 print
16 printLoop
18 searchArea
19 widthOfLoop
20 x
21 y
Installation
This module is written in 100% Pure Perl and, thus, it is easy to read, use, modify and install.
Standard Module::Build process for building and installing modules:
perl Build.PL
./Build
./Build test
./Build installAuthor
Copyright
Copyright (c) 2016-2018 Philip R Brenan.
This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.