From 60e9e3589254dc410b548c873ba3d1774d78a718 Mon Sep 17 00:00:00 2001
From: Dennis Eichhorn <spl1nes.com@googlemail.com>
Date: Sun, 13 Feb 2022 23:58:18 +0100
Subject: [PATCH] add basic tesseract cli support

---
 Ai/Ocr/Tesseract/TesseractOcr.php | 184 ++++++++++++++++++++++++++++++
 1 file changed, 184 insertions(+)
 create mode 100644 Ai/Ocr/Tesseract/TesseractOcr.php

diff --git a/Ai/Ocr/Tesseract/TesseractOcr.php b/Ai/Ocr/Tesseract/TesseractOcr.php
new file mode 100644
index 000000000..b1f6322e0
--- /dev/null
+++ b/Ai/Ocr/Tesseract/TesseractOcr.php
@@ -0,0 +1,184 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   phpOMS\Ai\Ocr\Tesseract
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Ai\Ocr\Tesseract;
+
+use phpOMS\System\File\PathException;
+
+/**
+ * Tesseract api
+ *
+ * @package phpOMS\Ai\Ocr\Tesseract
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class TesseractOcr
+{
+    /**
+     * Tesseract path.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $bin = '/usr/bin/tesseract';
+
+    /**
+     * Set tesseract binary.
+     *
+     * @param string $path tesseract path
+     *
+     * @return void
+     *
+     * @throws PathException This exception is thrown if the binary path doesn't exist
+     *
+     * @since 1.0.0
+     */
+    public static function setBin(string $path) : void
+    {
+        if (\realpath($path) === false) {
+            throw new PathException($path);
+        }
+
+        self::$bin = \realpath($path);
+    }
+
+    /**
+     * Run git command.
+     *
+     * @param string $cmd Command to run
+     *
+     * @return string[]
+     *
+     * @throws \Exception
+     *
+     * @since 1.0.0
+     */
+    private function run(string $cmd) : array
+    {
+        if (\strtolower((string) \substr(\PHP_OS, 0, 3)) == 'win') {
+            $cmd = 'cd ' . \escapeshellarg(\dirname(self::$bin))
+                . ' && ' . \basename(self::$bin)
+                . ' -C ' . \escapeshellarg($this->path) . ' '
+                . $cmd;
+        } else {
+            $cmd = \escapeshellarg(self::$bin)
+                . ' -C ' . \escapeshellarg($this->path) . ' '
+                . $cmd;
+        }
+
+        $pipes = [];
+        $desc  = [
+            1 => ['pipe', 'w'],
+            2 => ['pipe', 'w'],
+        ];
+
+        $resource = \proc_open($cmd, $desc, $pipes, $this->path, null);
+
+        if ($resource === false) {
+            throw new \Exception();
+        }
+
+        $stdout = \stream_get_contents($pipes[1]);
+        $stderr = \stream_get_contents($pipes[2]);
+
+        foreach ($pipes as $pipe) {
+            \fclose($pipe);
+        }
+
+        $status = \proc_close($resource);
+
+        if ($status == -1) {
+            throw new \Exception((string) $stderr);
+        }
+
+        return $this->parseLines(\trim($stdout === false ? '' : $stdout));
+    }
+
+    /**
+     * Parse lines.
+     *
+     * @param string $lines Result of git command
+     *
+     * @return string[]
+     *
+     * @since 1.0.0
+     */
+    private function parseLines(string $lines) : array
+    {
+        $lineArray = \preg_split('/\r\n|\n|\r/', $lines);
+        $lines     = [];
+
+        if ($lineArray === false) {
+            return $lines;
+        }
+
+        foreach ($lineArray as $line) {
+            $temp = \preg_replace('/\s+/', ' ', \trim($line, ' '));
+
+            if (!empty($temp)) {
+                $lines[] = $temp;
+            }
+        }
+
+        return $lines;
+    }
+
+    /**
+     * Prase image
+     *
+     * @param string $image     Image path
+     * @param array  $languages Languages to use
+     * @param int    $psm       Page segmentation mode (0 - 13)
+     *                              0    Orientation and script detection (OSD) only.
+     *                              1    Automatic page segmentation with OSD.
+     *                              2    Automatic page segmentation, but no OSD, or OCR.
+     *                              3    Fully automatic page segmentation, but no OSD. (Default)
+     *                              4    Assume a single column of text of variable sizes.
+     *                              5    Assume a single uniform block of vertically aligned text.
+     *                              6    Assume a single uniform block of text.
+     *                              7    Treat the image as a single text line.
+     *                              8    Treat the image as a single word.
+     *                              9    Treat the image as a single word in a circle.
+     *                              10   Treat the image as a single character.
+     *                              11   Sparse text. Find as much text as possible in no particular order.
+     *                              12   Sparse text with OSD.
+     *                              13   Raw line. Treat the image as a single text line, bypassing hacks that are Tesseract-specific.
+     * @param int    $oem       OCR engine modes
+     *                              0    Legacy engine only.
+     *                              1    Neural nets LSTM engine only.
+     *                              2    Legacy + LSTM engines.
+     *                              3    Default, based on what is available
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function parseImage(string $image, array $languages = ['eng'], int $psm = 3, int $oem = 3) : string
+    {
+        $this->run(
+            $image . ' '
+            . ($temp = \tempnam(\sys_get_temp_dir(), 'ocr_'))
+            . '--psm ' . $psm . ' '
+            . '--oem ' . $oem . ' '
+            . '-l ' . \implode('+', $languages)
+        );
+
+        $parsed = \file_get_contents($temp);
+
+        \unlink($temp);
+
+        return $parsed;
+    }
+}