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Merge pull request #691 from matiasdelellis/native-cwc
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Implement the Chinese Whispers clustering algorithm in PHP code.
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matiasdelellis authored Aug 23, 2023
2 parents 76fe598 + 5574532 commit 4ad739e
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Showing 8 changed files with 193 additions and 28 deletions.
2 changes: 1 addition & 1 deletion .github/workflows/coverage.yml
Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ jobs:
matrix:
php-versions: ['8.1']
databases: ['mysql']
server-versions: ['stable26']
server-versions: ['stable27']

name: php${{ matrix.php-versions }}-${{ matrix.databases }}-${{ matrix.server-versions }}

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2 changes: 1 addition & 1 deletion .github/workflows/phpunit.yml
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Expand Up @@ -19,7 +19,7 @@ jobs:
matrix:
php-versions: ['8.0', '8.1', '8.2']
databases: ['sqlite', 'mysql', 'pgsql']
server-versions: ['stable26']
server-versions: ['stable27']

name: php${{ matrix.php-versions }}-${{ matrix.databases }}-${{ matrix.server-versions }}

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2 changes: 1 addition & 1 deletion .github/workflows/static-analysis.yml
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Expand Up @@ -11,7 +11,7 @@ jobs:
runs-on: ubuntu-latest
strategy:
matrix:
ocp-version: ['dev-stable26']
ocp-version: ['dev-stable27']
name: Nextcloud ${{ matrix.ocp-version }}
steps:
- name: Checkout
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6 changes: 2 additions & 4 deletions appinfo/info.xml
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Expand Up @@ -16,7 +16,7 @@
- **🚀 Build your own thing:** FaceRecognition app is just a basic building block. Through FaceRecognition API, you can build your advanced scenarios - automatically add tags to images, connect contacts and persons, share images from specific person… We want to hear your ideas!
]]>
</description>
<version>0.9.20</version>
<version>0.9.30</version>
<licence>agpl</licence>
<author>Matias De lellis</author>
<author>Branko Kokanovic</author>
Expand All @@ -34,9 +34,7 @@
<screenshot>https://matiasdelellis.github.io/img/facerecognition/facerecognition-assign-initial-name.jpeg</screenshot>
<dependencies>
<php min-version="8.0" max-version="8.2" />
<lib>pdlib</lib>
<lib>bz2</lib>
<nextcloud min-version="26" max-version="27"/>
<nextcloud min-version="27" max-version="27"/>
</dependencies>
<repair-steps>
<uninstall>
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14 changes: 4 additions & 10 deletions lib/BackgroundJob/Tasks/CheckRequirementsTask.php
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Expand Up @@ -90,8 +90,10 @@ public function execute(FaceRecognitionContext $context) {
$phpMemory = MemoryLimits::getPhpMemory();
$this->logDebug("PHP Memory Limit: " . ($phpMemory > 0 ? $phpMemory : "Unknown"));

$this->logDebug("Clustering backend: " . (Requirements::pdlibLoaded() ? "pdlib" : "PHP (Not recommended."));

if ($this->imaginaryHelper->isEnabled()) {
$this->logDebug("Backend of images: Imaginary");
$this->logDebug("Image Backend: Imaginary");
$version = $this->imaginaryHelper->getVersion();
if ($version) {
$this->logDebug("Imaginary version: " . $version);
Expand All @@ -104,15 +106,7 @@ public function execute(FaceRecognitionContext $context) {
return false;
}
} else {
$this->logDebug("Backend of images: Imagick");
}

if (!Requirements::pdlibLoaded()) {
$error_message =
"The PDlib PHP extension is not loaded. Cannot continue without it." .
"Please read the documentation again about how to install the application: https://github.com/matiasdelellis/facerecognition/wiki/Installation";
$this->logInfo($error_message);
return false;
$this->logDebug("Image Backend: Imagick");
}

if (!Requirements::hasEnoughMemory()) {
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32 changes: 25 additions & 7 deletions lib/BackgroundJob/Tasks/CreateClustersTask.php
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
<?php
/**
* @copyright Copyright (c) 2017-2020 Matias De lellis <[email protected]>
* @copyright Copyright (c) 2017-2023 Matias De lellis <[email protected]>
* @copyright Copyright (c) 2018, Branko Kokanovic <[email protected]>
*
* @author Branko Kokanovic <[email protected]>
Expand Down Expand Up @@ -33,6 +33,9 @@
use OCA\FaceRecognition\Db\PersonMapper;

use OCA\FaceRecognition\Helper\Euclidean;
use OCA\FaceRecognition\Helper\Requirements;

use OCA\FaceRecognition\Clusterer\ChineseWhispers;

use OCA\FaceRecognition\Service\SettingsService;
/**
Expand Down Expand Up @@ -282,10 +285,9 @@ private function getNewClusters(array $faces): array {
// Clustering parameters
$sensitivity = $this->settingsService->getSensitivity();

// Create edges for chinese whispers
$edges = array();

if (version_compare(phpversion('pdlib'), '1.0.2', '>=')) {
if (Requirements::pdlibLoaded()) {
// Create edges (neighbors) for Chinese Whispers
$edges = array();
$faces_count = count($faces);
for ($i = 0; $i < $faces_count; $i++) {
$face1 = $faces[$i];
Expand All @@ -304,8 +306,14 @@ private function getNewClusters(array $faces): array {
}
}
}

// Given the edges get the list of labels (found clusters) for each face.
$newChineseClustersByIndex = dlib_chinese_whispers($edges);
} else {
// Create edges (neighbors) for Chinese Whispers
$edges = array();
$faces_count = count($faces);

for ($i = 0; $i < $faces_count; $i++) {
$face1 = $faces[$i];
if (!isset($face1->descriptor)) {
Expand All @@ -323,17 +331,27 @@ private function getNewClusters(array $faces): array {
}
}
}

// The clustering algorithm actually expects ordered lists.
$oedges = [];
ChineseWhispers::convert_unordered_to_ordered($edges, $oedges);
usort($oedges, function($a, $b) {
if ($a[0] === $b[0]) return $a[1] - $b[1];
return $a[0] - $b[0];
});

// Given the edges get the list of labels (found clusters) for each face.
$newChineseClustersByIndex = [];
ChineseWhispers::predict($oedges, $newChineseClustersByIndex);
}

$newChineseClustersByIndex = dlib_chinese_whispers($edges);
$newClusters = array();
for ($i = 0, $c = count($newChineseClustersByIndex); $i < $c; $i++) {
if (!isset($newClusters[$newChineseClustersByIndex[$i]])) {
$newClusters[$newChineseClustersByIndex[$i]] = array();
}
$newClusters[$newChineseClustersByIndex[$i]][] = $faces[$i]->id;
}

return $newClusters;
}

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159 changes: 159 additions & 0 deletions lib/Clusterer/ChineseWhispers.php
Original file line number Diff line number Diff line change
@@ -0,0 +1,159 @@
<?php
declare(strict_types=1);
/**
* @copyright Copyright (c) 2023, Matias De lellis
*
* @author Matias De lellis <[email protected]>
*
* @license AGPL-3.0-or-later
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/

namespace OCA\FaceRecognition\Clusterer;


/**
* This class implements the graph clustering algorithm described in the
* paper: Chinese Whispers - an Efficient Graph Clustering Algorithm and its
* Application to Natural Language Processing Problems by Chris Biemann.
*
* In particular, it tries to be a shameless copy of the original dlib
* implementation.
* - https://github.com/davisking/dlib/blob/master/dlib/clustering/chinese_whispers.h
*/
class ChineseWhispers {

/**
* Cluster the dataset by assigning a label to each sample.from the edges
*/
static public function predict(array &$edges, array &$labels, int $num_iterations = 100)
{
// To improve the stability of the clusters, we must
// iterate the neighbors in a pseudo-random way.
mt_srand(2023);

$labels = [];
if (count($edges) == 0)
return 0;

$neighbors = [];
self::find_neighbor_ranges($edges, $neighbors);

// Initialize the labels, each node gets a different label.
for ($i = 0; $i < count($neighbors); ++$i)
$labels[$i] = $i;

for ($iter = 0; $iter < count($neighbors)*$num_iterations; ++$iter)
{
// Pick a random node.
$idx = mt_rand()%count($neighbors);

// Count how many times each label happens amongst our neighbors.
$labels_to_counts = [];
$end = $neighbors[$idx][1];

for ($i = $neighbors[$idx][0]; $i != $end; ++$i)
{
$iLabelFirst = $edges[$i][1];
$iLabel = $labels[$iLabelFirst];
if (isset($labels_to_counts[$iLabel]))
$labels_to_counts[$iLabel]++;
else
$labels_to_counts[$iLabel] = 1;
}

// find the most common label
// std::map<unsigned long, double>::iterator i;
$best_score = PHP_INT_MIN;
$best_label = $labels[$idx];
foreach ($labels_to_counts as $key => $value)
{
if ($value > $best_score)
{
$best_score = $value;
$best_label = $key;
}
}

$labels[$idx] = $best_label;
}

// Remap the labels into a contiguous range. First we find the
// mapping.
$label_remap = [];
for ($i = 0; $i < count($labels); ++$i)
{
$next_id = count($label_remap);
if (!isset($label_remap[$labels[$i]]))
$label_remap[$labels[$i]] = $next_id;
}
// now apply the mapping to all the labels.
for ($i = 0; $i < count($labels); ++$i)
{
$labels[$i] = $label_remap[$labels[$i]];
}

return count($label_remap);
}

static function find_neighbor_ranges (&$edges, &$neighbors) {
// setup neighbors so that [neighbors[i].first, neighbors[i].second) is the range
// within edges that contains all node i's edges.
$num_nodes = self::max_index_plus_one($edges);
for ($i = 0; $i < $num_nodes; ++$i) $neighbors[$i] = [0, 0];
$cur_node = 0;
$start_idx = 0;
for ($i = 0; $i < count($edges); ++$i)
{
if ($edges[$i][0] != $cur_node)
{
$neighbors[$cur_node] = [$start_idx, $i];
$start_idx = $i;
$cur_node = $edges[$i][0];
}
}
if (count($neighbors) !== 0)
$neighbors[$cur_node] = [$start_idx, count($edges)];
}

static function max_index_plus_one ($pairs): int {
if (count($pairs) === 0)
{
return 0;
}
else {
$max_idx = 0;
for ($i = 0; $i < count($pairs); ++$i)
{
if ($pairs[$i][0] > $max_idx)
$max_idx = $pairs[$i][0];
if ($pairs[$i][1] > $max_idx)
$max_idx = $pairs[$i][1];
}
return $max_idx + 1;
}
}

static function convert_unordered_to_ordered (&$edges, &$out_edges)
{
$out_edges = [];
for ($i = 0; $i < count($edges); ++$i)
{
$out_edges[] = [$edges[$i][0], $edges[$i][1]];
if ($edges[$i][0] != $edges[$i][1])
$out_edges[] = [$edges[$i][1], $edges[$i][0]];
}
}
}
4 changes: 0 additions & 4 deletions lib/Model/ExternalModel/ExternalModel.php
Original file line number Diff line number Diff line change
Expand Up @@ -87,10 +87,6 @@ public function isInstalled(): bool {
}

public function meetDependencies(string &$error_message): bool {
if (!extension_loaded('pdlib')) {
$error_message = "The PDlib PHP extension is not loaded.";
return false;
}
if (is_null($this->settingsService->getExternalModelUrl())) {
$error_message = "You still need to configure the URL of the service running the model.";
return false;
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