AI-MXNet
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lib/AI/MXNet/Image.pm view on Meta::CPAN
package AI::MXNet::Image;
use strict;
use warnings;
use Scalar::Util qw(blessed);
use AI::MXNet::Base;
use AI::MXNet::Function::Parameters;
=head1 NAME
AI::MXNet:Image - Read individual image files and perform augmentations.
=cut
=head2 imdecode
Decode an image from string. Requires OpenCV to work.
Parameters
----------
$buf : str, array ref, pdl, ndarray
Binary image data.
:$flag : int
0 for grayscale. 1 for colored.
:$to_rgb : int
0 for BGR format (OpenCV default). 1 for RGB format (MXNet default).
:$out : NDArray
Output buffer. Do not specify for automatic allocation.
=cut
method imdecode(Str|PDL $buf, Int :$flag=1, Int :$to_rgb=1, Maybe[AI::MXNet::NDArray] :$out=)
{
if(not ref $buf)
{
my $pdl_type = PDL::Type->new(DTYPE_MX_TO_PDL->{'uint8'});
my $len; { use bytes; $len = length $buf; }
my $pdl = PDL->new_from_specification($pdl_type, $len);
${$pdl->get_dataref} = $buf;
$pdl->upd_data;
$buf = $pdl;
}
if(not (blessed $buf and $buf->isa('AI::MXNet::NDArray')))
{
$buf = AI::MXNet::NDArray->array($buf, dtype=>'uint8');
}
return AI::MXNet::NDArray->_cvimdecode($buf, { flag => $flag, to_rgb => $to_rgb, ($out ? (out => $out) : ()) });
}
=head2 scale_down
Scale down crop size if it's bigger than the image size.
Parameters:
-----------
Shape $src_size
Shape $size
Returns:
--------
($w, $h)
=cut
method scale_down(Shape $src_size, Shape $size)
{
my ($w, $h) = @{ $size };
my ($sw, $sh) = @{ $src_size };
if($sh < $h)
{
($w, $h) = (($w*$sh)/$h, $sh);
}
if($sw < $w)
{
($w, $h) = ($sw, ($h*$sw)/$w);
}
return (int($w), int($h));
}
=head2 resize_short
Resize shorter edge to the size.
Parameters:
-----------
AI::MXNet::NDArray $src
Int $size
Int $interp=2
Returns:
--------
AI::MXNet::NDArray $resized_image
=cut
method resize_short(AI::MXNet::NDArray $src, Int $size, Int $interp=2)
{
my ($new_h, $new_w);
my ($h, $w) = @{ $src->shape };
if($h > $w)
{
($new_h, $new_w) = ($size*$h/$w, $size);
lib/AI/MXNet/Image.pm view on Meta::CPAN
CodeRef that accepts AI::MXNet::NDArray $src as input
and returns [__PACKAGE__->color_normalize($src, $mean, $std)]
=cut
method ColorNormalizeAug(PDL $mean, PDL $std)
{
$mean = AI::MXNet::NDArray->array($mean);
$std = AI::MXNet::NDArray->array($std);
my $aug = sub { my $src = shift;
return [__PACKAGE__->color_normalize($src, $mean, $std)]
};
return $aug;
}
=head2 HorizontalFlipAug
Makes "Random horizontal flipping" closure.
Parameters:
-----------
Num $p < 1
Returns:
--------
CodeRef that accepts AI::MXNet::NDArray $src as input
and returns [$p > rand ? AI::MXNet::NDArray->flip($src, axis=1>) : $src]
=cut
method HorizontalFlipAug(Num $p)
{
my $aug = sub { my $src = shift;
return [$p > rand() ? AI::MXNet::NDArray->flip($src, { axis=>1 }) : $src]
};
return $aug;
}
=head2 CastAug
Makes "Cast to float32" closure.
Returns:
--------
CodeRef that accepts AI::MXNet::NDArray $src as input
and returns [$src->astype('float32')]
=cut
method CastAug()
{
my $aug = sub { my $src = shift;
return [$src->astype('float32')]
};
return $aug;
}
=head2 CreateAugmenter
Create augumenter list
Parameters:
-----------
Shape :$data_shape,
Bool :$resize=0,
Bool :$rand_crop=0,
Bool :$rand_resize=0,
Bool :$rand_mirror=0,
Maybe[Num|PDL] :$mean=,
Maybe[Num|PDL] :$std=,
Num :$brightness=0,
Num :$contrast=0,
Num :$saturation=0,
Num :$pca_noise=0,
Int :$inter_method=2
=cut
method CreateAugmenter(
Shape :$data_shape,
Bool :$resize=0,
Bool :$rand_crop=0,
Bool :$rand_resize=0,
Bool :$rand_mirror=0,
Maybe[Num|PDL] :$mean=,
Maybe[Num|PDL] :$std=,
Num :$brightness=0,
Num :$contrast=0,
Num :$saturation=0,
Num :$pca_noise=0,
Int :$inter_method=2
)
{
my @auglist;
if($resize > 0)
{
push @auglist, __PACKAGE__->ResizeAug($resize, $inter_method);
}
my $crop_size = [$data_shape->[2], $data_shape->[1]];
if($rand_resize)
{
assert($rand_crop);
push @auglist, __PACKAGE__->RandomSizedCropAug($crop_size, 0.3, [3.0/4.0, 4.0/3.0], $inter_method);
}
elsif($rand_crop)
{
push @auglist, __PACKAGE__->RandomCropAug($crop_size, $inter_method);
}
else
{
push @auglist, __PACKAGE__->CenterCropAug($crop_size, $inter_method);
}
if($rand_mirror)
{
push @auglist, __PACKAGE__->HorizontalFlipAug(0.5);
}
push @auglist, __PACKAGE__->CastAug;
if($brightness or $contrast or $saturation)
{
push @auglist, __PACKAGE__->ColorJitterAug($brightness, $contrast, $saturation);
}
if($pca_noise > 0)
{
my $eigval = AI::MXNet::NDArray->array([55.46, 4.794, 1.148])->aspdl;
my $eigvec = AI::MXNet::NDArray->array([[-0.5675, 0.7192, 0.4009],
[-0.5808, -0.0045, -0.8140],
[-0.5836, -0.6948, 0.4203]])->aspdl;
push @auglist, __PACKAGE__->LightingAug($pca_noise, $eigval, $eigvec);
}
if($mean)
{
$mean = AI::MXNet::NDArray->array([123.68, 116.28, 103.53])->aspdl;
}
if($std)
{
$std = AI::MXNet::NDArray->array([58.395, 57.12, 57.375])->aspdl;
}
if(defined $mean)
{
assert(defined $std);
push @auglist, __PACKAGE__->ColorNormalizeAug($mean, $std);
}
return \@auglist;
}
method ImageIter(@args) { AI::MXNet::ImageIter->new(@args) }
package AI::MXNet::ImageIter;
use Mouse;
use AI::MXNet::Base;
extends 'AI::MXNet::DataIter';
=head1 NAME
AI::MXNet::ImageIter - Image data iterator.
=cut
=head1 DESCRIPTION
Image data iterator with a large number of augumentation choices.
Supports reading from both .rec files and raw image files with image list.
To load from .rec files, please specify path_imgrec. Also specify path_imgidx
to use data partition (for distributed training) or shuffling.
To load from raw image files, specify path_imglist and path_root.
Parameters
----------
batch_size : Int
Number of examples per batch
data_shape : Shape
Data shape in (channels, height, width).
For now, only RGB image with 3 channels is supported.
label_width : Int
dimension of label
path_imgrec : str
path to image record file (.rec).
Created with tools/im2rec.py or bin/im2rec
path_imglist : str
path to image list (.lst)
Created with tools/im2rec.py or with custom script.
Format: index\t[one or more label separated by \t]\trelative_path_from_root
imglist: array ref
a list of image with the label(s)
each item is a list [imagelabel: float or array ref of float, imgpath]
path_root : str
Root folder of image files
path_imgidx : str
Path to image index file. Needed for partition and shuffling when using .rec source.
shuffle : bool
Whether to shuffle all images at the start of each iteration.
Can be slow for HDD.
part_index : int
Partition index
num_parts : int
Total number of partitions.
data_name='data' Str
label_name='softmax_label' Str
kwargs : hash ref with any additional arguments for augmenters
=cut
has 'batch_size' => (is => 'ro', isa => 'Int', required => 1);
has 'data_shape' => (is => 'ro', isa => 'Shape', required => 1);
has 'label_width' => (is => 'ro', isa => 'Int', default => 1);
has 'data_name' => (is => 'ro', isa => 'Str', default => 'data');
has 'label_name' => (is => 'ro', isa => 'Str', default => 'softmax_label');
has [qw/path_imgrec
path_imglist
path_root
path_imgidx
/] => (is => 'ro', isa => 'Str');
has 'shuffle' => (is => 'ro', isa => 'Bool', default => 0);
has 'part_index' => (is => 'ro', isa => 'Int', default => 0);
has 'num_parts' => (is => 'ro', isa => 'Int', default => 0);
has 'aug_list' => (is => 'rw', isa => 'ArrayRef[CodeRef]');
has 'imglist' => (is => 'rw', isa => 'ArrayRef|HashRef');
has 'kwargs' => (is => 'ro', isa => 'HashRef');
has [qw/imgidx
imgrec
seq
cur
provide_data
provide_label
/] => (is => 'rw', init_arg => undef);
sub BUILD
{
my $self = shift;
assert($self->path_imgrec or $self->path_imglist or ref $self->imglist eq 'ARRAY');
if($self->path_imgrec)
{
print("loading recordio...\n");
if($self->path_imgidx)
{
$self->imgrec(
AI::MXNet::IndexedRecordIO->new(
idx_path => $self->path_imgidx,
uri => $self->path_imgrec,
flag => 'r'
)
);
$self->imgidx([@{ $self->imgrec->keys }]);
}
else
{
$self->imgrec(AI::MXNet::RecordIO->new(uri => $self->path_imgrec, flag => 'r'));
}
}
my %imglist;
my @imgkeys;
if($self->path_imglist)
{
print("loading image list...\n");
open(my $f, $self->path_imglist) or confess("can't open ${\ $self->path_imglist } : $!");
while(my $line = <$f>)
{
chomp($line);
my @line = split(/\t/, $line);
my $label = AI::MXNet::NDArray->array([@line[1..@line-2]]);
my $key = $line[0];
$imglist{$key} = [$label, $line[-1]];
push @imgkeys, $key;
}
$self->imglist(\%imglist);
}
elsif(ref $self->imglist eq 'ARRAY')
{
print("loading image list...\n");
my %result;
my $index = 1;
for my $img (@{ $self->imglist })
{
my $key = $index++;
my $label;
if(not ref $img->[0])
{
$label = AI::MXNet::NDArray->array([$img->[0]]);
}
else
{
$label = AI::MXNet::NDArray->array($img->[0]);
$result{$key} = [$label, $img->[1]];
push @imgkeys, $key;
}
}
$self->imglist(\%result);
}
assert(@{ $self->data_shape } == 3 and $self->data_shape->[0] == 3);
$self->provide_data([
AI::MXNet::DataDesc->new(
name => $self->data_name,
shape => [$self->batch_size, @{ $self->data_shape }]
)
]);
if($self->label_width > 1)
{
$self->provide_label([
AI::MXNet::DataDesc->new(
name => $self->label_name,
shape => [$self->batch_size, $self->label_width]
)
]);
}
else
{
$self->provide_label([
AI::MXNet::DataDesc->new(
name => $self->label_name,
shape => [$self->batch_size]
)
]);
}
if(not defined $self->imgrec)
{
$self->seq(\@imgkeys);
}
elsif($self->shuffle or $self->num_parts > 1)
{
assert(defined $self->imgidx);
$self->seq($self->imgidx);
}
if($self->num_parts > 1)
{
assert($self->part_index < $self->num_parts);
my $N = @{ $self->seq };
my $C = $N/$self->num_parts;
$self->seq([@{ $self->seq }[$self->part_index*$C..($self->part_index+1)*$C-1]]);
}
if(defined $self->aug_list or defined $self->kwargs)
{
$self->aug_list(AI::MXNet::Image->CreateAugmenter(data_shape => $self->data_shape, %{ $self->kwargs//{} }));
}
else
{
$self->aug_list([]);
}
$self->cur(0);
$self->reset();
}
method reset()
{
if($self->shuffle)
{
@{ $self->seq } = List::Util::shuffle(@{ $self->seq });
}
if(defined $self->imgrec)
{
$self->imgrec->reset;
}
$self->cur(0);
}
method next_sample()
{
if(defined $self->seq)
{
return undef if($self->cur >= @{ $self->seq });
my $idx = $self->seq->[$self->cur];
$self->cur($self->cur + 1);
if(defined $self->imgrec)
{
my $s = $self->imgrec->read_idx($idx);
my ($header, $img) = AI::MXNet::RecordIO->unpack($s);
if(not defined $self->imglist)
{
return ($header->label, $img);
}
else
{
return ($self->imglist->{$idx}[0], $img);
}
}
else
{
my ($label, $fname) = @{ $self->imglist->{$idx} };
if(not defined $self->imgrec)
{
open(F, $self->path_root . "/$fname") or confess("can't open $fname $!");
my $img;
{ local $/ = undef; $img = <F> };
close(F);
return ($label, $img);
}
}
}
else
{
my $s = $self->imgrec->read;
return undef if(not defined $s);
my ($header, $img) = AI::MXNet::RecordIO->unpack($s);
return ($header->label, $img)
}
}
method next()
{
my $batch_size = $self->batch_size;
my ($c, $h, $w) = @{ $self->data_shape };
my $batch_data = AI::MXNet::NDArray->empty([$batch_size, $c, $h, $w]);
my $batch_label = AI::MXNet::NDArray->empty(@{$self->provide_label->[0]}[1]);
my $i = 0;
while ($i < $batch_size)
{
my ($label, $s) = $self->next_sample;
last if not defined $label;
my $data = [AI::MXNet::Image->imdecode($s)];
if(@{ $data->[0]->shape } == 0)
{
AI::MXNet::Logging->debug('Invalid image, skipping.');
next;
}
for my $aug (@{ $self->aug_list })
{
$data = [map { @{ $aug->($_) } } @$data];
}
for my $d (@$data)
{
assert(($i < $batch_size), 'Batch size must be multiples of augmenter output length');
$batch_data->at($i) .= AI::MXNet::NDArray->transpose($d, { axes=>[2, 0, 1] });
$batch_label->at($i) .= $label;
$i++;
}
}
return undef if not $i;
return AI::MXNet::DataBatch->new(data=>[$batch_data], label=>[$batch_label], pad => $batch_size-$i);
}
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