AI-TensorFlow-Libtensorflow

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lib/AI/TensorFlow/Libtensorflow/Manual/Notebook/InferenceUsingTFHubCenterNetObjDetect.pod  view on Meta::CPAN

    memcpy scalar_to_pointer( ${$pdl->get_dataref} ),
        scalar_to_pointer( ${$t->Data} ),
        $t->ByteSize;
    $pdl->upd_data;

    $pdl;
}

# image_size => [width, height] (but usually square images)
my %model_name_to_params = (
    centernet_hourglass_512x512 => {
        handle => 'https://tfhub.dev/tensorflow/centernet/hourglass_512x512/1',
        image_size => [ 512, 512 ],
    },
);

my $model_name = 'centernet_hourglass_512x512';

say "Selected model: $model_name : $model_name_to_params{$model_name}{handle}";

my $model_uri = URI->new( $model_name_to_params{$model_name}{handle} );
$model_uri->query_form( 'tf-hub-format' => 'compressed' );
my $model_base = substr( $model_uri->path, 1 ) =~ s,/,_,gr;
my $model_archive_path = "${model_base}.tar.gz";

my $http = HTTP::Tiny->new;

for my $download ( [ $model_uri  => $model_archive_path ],) {
    my ($uri, $path) = @$download;
    say "Downloading $uri to $path";
    next if -e $path;
    $http->mirror( $uri, $path );
}

use Archive::Extract;
my $ae = Archive::Extract->new( archive => $model_archive_path );
die "Could not extract archive" unless $ae->extract( to => $model_base );

my $saved_model = path($model_base)->child('saved_model.pb');
say "Saved model is in $saved_model" if -f $saved_model;

# Get the labels
my $response = $http->get('https://raw.githubusercontent.com/tensorflow/models/a4944a57ad2811e1f6a7a87589a9fc8a776e8d3c/object_detection/data/mscoco_label_map.pbtxt');

my %labels_map = $response->{content} =~ m<
(?:item \s+ \{  \s+
  \Qname:\E \s+ "[^"]+" \s+
  \Qid:\E   \s+ (\d+) \s+
  \Qdisplay_name:\E \s+ "([^"]+)" \s+
})+
>sgx;

my $label_count = List::Util::max keys %labels_map;

say "We have a label count of $label_count. These labels include: ",
    join ", ", List::Util::head( 5, @labels_map{ sort keys %labels_map } );

my @tags = ( 'serve' );

if( File::Which::which('saved_model_cli')) {
    local $ENV{TF_CPP_MIN_LOG_LEVEL} = 3; # quiet the TensorFlow logger for the following command
    system(qw(saved_model_cli show),
        qw(--dir)           => $model_base,
        qw(--tag_set)       => join(',', @tags),
        qw(--signature_def) => 'serving_default'
    ) == 0 or die "Could not run saved_model_cli";
} else {
    say "Install the tensorflow Python package to get the `saved_model_cli` command.";
}

my $opt = AI::TensorFlow::Libtensorflow::SessionOptions->New;

my $graph = AI::TensorFlow::Libtensorflow::Graph->New;
my $session = AI::TensorFlow::Libtensorflow::Session->LoadFromSavedModel(
    $opt, undef, $model_base, \@tags, $graph, undef, $s
);
AssertOK($s);

my %ops = (
    in  => {
        op   =>  $graph->OperationByName('serving_default_input_tensor'),
        dict => {
            input_tensor => 0,
        }
    },
    out => {
        op => $graph->OperationByName('StatefulPartitionedCall'),
        dict => {
            detection_boxes   => 0,
            detection_classes => 1,
            detection_scores  => 2,
            num_detections    => 3,
        }
    },
);

my %outputs;

%outputs = map {
    my $put_type = $_;
    my $op = $ops{$put_type}{op};
    my $port_dict = $ops{$put_type}{dict};

   $put_type => +{
        map {
            my $dict_key = $_;
            my $index = $port_dict->{$_};
            $dict_key => AI::TensorFlow::Libtensorflow::Output->New( {
                oper => $op,
                index => $index,
            });
        } keys %$port_dict
     }
} keys %ops;

p %outputs;

use HTML::Tiny;

my %images_for_test_to_uri = (
    "beach_scene" => 'https://github.com/tensorflow/models/blob/master/research/object_detection/test_images/image2.jpg?raw=true',
);

my @image_names = sort keys %images_for_test_to_uri;
my $h = HTML::Tiny->new;

my $image_name = 'beach_scene';
if( IN_IPERL ) {

lib/AI/TensorFlow/Libtensorflow/Manual/Notebook/InferenceUsingTFHubCenterNetObjDetect.pod  view on Meta::CPAN

            [ object => [ "rect" =>
                from => $from_xy, to => $to_xy,
                qq{front fs empty border lc rgb "$lc_rgb" lw 5} ], ],
            [ label => [
                sprintf("%s: %.1f",
                    $subset{detection_class_labels}[$idx],
                    100*$subset{detection_scores}->at($idx,0) ) =>
                at => $label_xy, 'left',
                offset => 'character 0,-0.25',
                qq{font ",12" boxed front tc rgb "#ffffff"} ], ],
        )
    } 0..$subset{detection_boxes}->dim(1)-1
);

$gp->plot(
    topcmds => q{set style textbox opaque fc "#505050f0" noborder},
    square => 1,
    yrange => [$pdl_images[0]->dim(2),0],
    with => 'image', $pdl_images[0],
);

$gp->close;

IPerl->png( bytestream => path($plot_output_path)->slurp_raw ) if IN_IPERL;

use Filesys::DiskUsage qw/du/;

my $total = du( { 'human-readable' => 1, dereference => 1 },
    $model_archive_path, $model_base );

say "Disk space usage: $total"; undef;

__END__

=pod

=encoding UTF-8

=head1 NAME

AI::TensorFlow::Libtensorflow::Manual::Notebook::InferenceUsingTFHubCenterNetObjDetect - Using TensorFlow to do object detection using a pre-trained model

=head1 SYNOPSIS

The following tutorial is based on the L<TensorFlow Hub Object Detection Colab notebook|https://www.tensorflow.org/hub/tutorials/tf2_object_detection>. It uses a pre-trained model based on the I<CenterNet> architecture trained on the I<COCO 2017> dat...

Some of this code is identical to that of C<InferenceUsingTFHubMobileNetV2Model> notebook. Please look there for an explanation for that code. As stated there, this will later be wrapped up into a high-level library to hide the details behind an API.

=head1 COLOPHON

The following document is either a POD file which can additionally be run as a Perl script or a Jupyter Notebook which can be run in L<IPerl|https://p3rl.org/Devel::IPerl> (viewable online at L<nbviewer|https://nbviewer.org/github/EntropyOrg/perl-AI-...

=over

=item *

C<PDL::Graphics::Gnuplot> requires C<gnuplot>.

=back

If you are running the code, you may optionally install the L<C<tensorflow> Python package|https://www.tensorflow.org/install/pip> in order to access the C<saved_model_cli> command, but this is only used for informational purposes.

=head1 TUTORIAL

=head2 Load the library

First, we need to load the C<AI::TensorFlow::Libtensorflow> library and more helpers. We then create an C<AI::TensorFlow::Libtensorflow::Status> object and helper function to make sure that the calls to the C<libtensorflow> C library are working prop...

  use strict;
  use warnings;
  use utf8;
  use constant IN_IPERL => !! $ENV{PERL_IPERL_RUNNING};
  no if IN_IPERL, warnings => 'redefine'; # fewer messages when re-running cells
  
  use feature qw(say state postderef);
  use Syntax::Construct qw(each-array);
  
  use lib::projectroot qw(lib);
  
  BEGIN {
      if( IN_IPERL ) {
          $ENV{TF_CPP_MIN_LOG_LEVEL} = 3;
      }
      require AI::TensorFlow::Libtensorflow;
  }
  
  use URI ();
  use HTTP::Tiny ();
  use Path::Tiny qw(path);
  
  use File::Which ();
  
  use List::Util 1.56 qw(mesh);
  
  use Data::Printer ( output => 'stderr', return_value => 'void', filters => ['PDL'] );
  use Data::Printer::Filter::PDL ();
  use Text::Table::Tiny qw(generate_table);
  
  use Imager;
  
  my $s = AI::TensorFlow::Libtensorflow::Status->New;
  sub AssertOK {
      die "Status $_[0]: " . $_[0]->Message
          unless $_[0]->GetCode == AI::TensorFlow::Libtensorflow::Status::OK;
      return;
  }
  AssertOK($s);

And create helpers for converting between C<PDL> ndarrays and C<TFTensor> ndarrays.

  use PDL;
  use AI::TensorFlow::Libtensorflow::DataType qw(FLOAT UINT8);
  
  use FFI::Platypus::Memory qw(memcpy);
  use FFI::Platypus::Buffer qw(scalar_to_pointer);
  
  sub FloatPDLTOTFTensor {
      my ($p) = @_;
      return AI::TensorFlow::Libtensorflow::Tensor->New(
          FLOAT, [ reverse $p->dims ], $p->get_dataref, sub { undef $p }
      );

lib/AI/TensorFlow/Libtensorflow/Manual/Notebook/InferenceUsingTFHubCenterNetObjDetect.pod  view on Meta::CPAN

      centernet_hourglass_512x512 => {
          handle => 'https://tfhub.dev/tensorflow/centernet/hourglass_512x512/1',
          image_size => [ 512, 512 ],
      },
  );
  
  my $model_name = 'centernet_hourglass_512x512';
  
  say "Selected model: $model_name : $model_name_to_params{$model_name}{handle}";

We download the model to the current directory and then extract the model to a folder with the name given in C<$model_base>.

  my $model_uri = URI->new( $model_name_to_params{$model_name}{handle} );
  $model_uri->query_form( 'tf-hub-format' => 'compressed' );
  my $model_base = substr( $model_uri->path, 1 ) =~ s,/,_,gr;
  my $model_archive_path = "${model_base}.tar.gz";
  
  my $http = HTTP::Tiny->new;
  
  for my $download ( [ $model_uri  => $model_archive_path ],) {
      my ($uri, $path) = @$download;
      say "Downloading $uri to $path";
      next if -e $path;
      $http->mirror( $uri, $path );
  }
  
  use Archive::Extract;
  my $ae = Archive::Extract->new( archive => $model_archive_path );
  die "Could not extract archive" unless $ae->extract( to => $model_base );
  
  my $saved_model = path($model_base)->child('saved_model.pb');
  say "Saved model is in $saved_model" if -f $saved_model;

We need to download the COCO 2017 classification labels and parse out the mapping from the numeric index to the textual descriptions.

  # Get the labels
  my $response = $http->get('https://raw.githubusercontent.com/tensorflow/models/a4944a57ad2811e1f6a7a87589a9fc8a776e8d3c/object_detection/data/mscoco_label_map.pbtxt');
  
  my %labels_map = $response->{content} =~ m<
  (?:item \s+ \{  \s+
    \Qname:\E \s+ "[^"]+" \s+
    \Qid:\E   \s+ (\d+) \s+
    \Qdisplay_name:\E \s+ "([^"]+)" \s+
  })+
  >sgx;
  
  my $label_count = List::Util::max keys %labels_map;
  
  say "We have a label count of $label_count. These labels include: ",
      join ", ", List::Util::head( 5, @labels_map{ sort keys %labels_map } );

=head2 Load the model and session

We define the tag set C<[ 'serve' ]> which we will use to load the model.

  my @tags = ( 'serve' );

We can examine what computations are contained in the graph in terms of the names of the inputs and outputs of an operation found in the graph by running C<saved_model_cli>.

  if( File::Which::which('saved_model_cli')) {
      local $ENV{TF_CPP_MIN_LOG_LEVEL} = 3; # quiet the TensorFlow logger for the following command
      system(qw(saved_model_cli show),
          qw(--dir)           => $model_base,
          qw(--tag_set)       => join(',', @tags),
          qw(--signature_def) => 'serving_default'
      ) == 0 or die "Could not run saved_model_cli";
  } else {
      say "Install the tensorflow Python package to get the `saved_model_cli` command.";
  }

The above C<saved_model_cli> output shows that the model input is at C<serving_default_input_tensor:0> which means the operation named C<serving_default_input_tensor> at index C<0> and there are multiple outputs with different shapes.

Per the L<model description|https://tfhub.dev/tensorflow/centernet/hourglass_512x512/1> on TensorFlow Hub:

=over 2

B<Inputs>

A three-channel image of variable size - the model does NOT support batching. The input tensor is a C<tf.uint8> tensor with shape [1, height, width, 3] with values in [0, 255].

B<Outputs>

The output dictionary contains:

=over

=item -

C<num_detections>: a C<tf.int> tensor with only one value, the number of detections [N].

=item -

C<detection_boxes>: a C<tf.float32> tensor of shape [N, 4] containing bounding box coordinates in the following order: [ymin, xmin, ymax, xmax].

=item -

C<detection_classes>: a C<tf.int> tensor of shape [N] containing detection class index from the label file.

=item -

C<detection_scores>: a C<tf.float32> tensor of shape [N] containing detection scores.

=back

=back

Note that the above documentation has two errors: both C<num_detections> and C<detection_classes> are not of type C<tf.int>, but are actually C<tf.float32>.

Now we can load the model from that folder with the tag set C<[ 'serve' ]> by using the C<LoadFromSavedModel> constructor to create a C<::Graph> and a C<::Session> for that graph.

  my $opt = AI::TensorFlow::Libtensorflow::SessionOptions->New;
  
  my $graph = AI::TensorFlow::Libtensorflow::Graph->New;
  my $session = AI::TensorFlow::Libtensorflow::Session->LoadFromSavedModel(
      $opt, undef, $model_base, \@tags, $graph, undef, $s
  );
  AssertOK($s);

So let's use the names from the C<saved_model_cli> output to create our C<::Output> C<ArrayRef>s.

  my %ops = (
      in  => {
          op   =>  $graph->OperationByName('serving_default_input_tensor'),
          dict => {
              input_tensor => 0,
          }
      },
      out => {



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