基于 PHP 的员工电脑桌面监控软件中图像差分算法的设计与实现研究

class DesktopMonitoringSystem {
    private $blockSize = 16; // 图像分块尺寸
    private $threshold = 30; // 变化阈值
    private $monitoringDir = '/path/to/screenshots/'; // 截图存储路径
    private $logFile = '/path/to/monitoring.log'; // 日志文件路径
    // 类方法定义...
}

/**
 * 执行双图像差异对比分析
 * @param string $imagePath1 首帧图像存储路径
 * @param string $imagePath2 次帧图像存储路径
 * @return array 包含差异统计信息的关联数组
 */
public function compareImages($imagePath1, $imagePath2) {
    $image1 = imagecreatefrompng($imagePath1);
    $image2 = imagecreatefrompng($imagePath2);
    $width = imagesx($image1);
    $height = imagesy($image1);
    $totalBlocks = 0;
    $changedBlocks = 0;
    $changedAreas = [];
    // 分块迭代对比
    for ($y = 0; $y < $height; $y += $this->blockSize) {
        for ($x = 0; $x < $width; $x += $this->blockSize) {
            $totalBlocks++;
            $blockDiff = $this->compareBlock($image1, $image2, $x, $y);
            if ($blockDiff > $this->threshold) {
                $changedBlocks++;
                $changedAreas[] = [
                    'x' => $x,
                    'y' => $y,
                    'width' => min($this->blockSize, $width - $x),
                    'height' => min($this->blockSize, $height - $y),
                    'diff' => $blockDiff
                ];
            }
        }
    }
    imagedestroy($image1);
    imagedestroy($image2);
    return [
        'totalBlocks' => $totalBlocks,
        'changedBlocks' => $changedBlocks,
        'changePercentage' => ($changedBlocks / $totalBlocks) * 100,
        'changedAreas' => $changedAreas
    ];
}

/**
 * 计算指定图像块的差异度指标
 * @param resource $image1 首帧图像资源句柄
 * @param resource $image2 次帧图像资源句柄
 * @param int $x 图像块横向起始坐标
 * @param int $y 图像块纵向起始坐标
 * @return float 标准化后的差异度数值
 */
private function compareBlock($image1, $image2, $x, $y) {
    $diffSum = 0;
    $pixels = 0;
    for ($yi = 0; $yi < $this->blockSize; $yi++) {
        if ($y + $yi >= imagesy($image1)) break;
        for ($xi = 0; $xi < $this->blockSize; $xi++) {
            if ($x + $xi >= imagesx($image1)) break;
            $rgb1 = imagecolorat($image1, $x + $xi, $y + $yi);
            $rgb2 = imagecolorat($image2, $x + $xi, $y + $yi);
            $r1 = ($rgb1 >> 16) & 0xFF;
            $g1 = ($rgb1 >> 8) & 0xFF;
            $b1 = $rgb1 & 0xFF;
            $r2 = ($rgb2 >> 16) & 0xFF;
            $g2 = ($rgb2 >> 8) & 0xFF;
            $b2 = $rgb2 & 0xFF;
            // 累计像素差异
            $diffSum += abs($r1 - $r2) + abs($g1 - $g2) + abs($b1 - $b2);
            $pixels++;
        }
    }
    // 计算平均差异值
    return $pixels > 0? ($diffSum / ($pixels * 3)) : 0;
}

/**
 * 对图像变化区域进行可视化标注
 * @param string $baseImagePath 原始图像文件路径
 * @param array $changedAreas 包含变化区域信息的数组
 * @param string $outputPath 标注后图像输出路径
 */
public function highlightChanges($baseImagePath, $changedAreas, $outputPath) {
    $image = imagecreatefrompng($baseImagePath);
    $red = imagecolorallocate($image, 255, 0, 0);
    foreach ($changedAreas as $area) {
        imagerectangle($image,
            $area['x'], $area['y'],
            $area['x'] + $area['width'], $area['y'] + $area['height'],
            $red);
    }
    imagepng($image, $outputPath);
    imagedestroy($image);
}

/**
 * 将监控数据上传至远程服务器
 * @param array $data 包含监控信息的关联数组
 * @return string 服务器响应内容
 */
public function uploadMonitoringData($data) {
    $ch = curl_init('https://www.vipshare.com/api/monitoring/upload');
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
    $response = curl_exec($ch);
    curl_close($ch);
    return $response;
}