Initial commit

src/SimpleImageCompressor.php

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+<?php
+/**
+ * This is a simple PHP image compressor which allows you to compress any image easily on the fly.
+ * This lib actually compressing and resizing image saving its original proportion
+ * Geckon01(c) 2023
+ * Class SimpleImageCompressor
+ */
+
+namespace geckon01\SimpleImageCompressor;
+
+/**
+ * Class SimpleImageCompressor
+ * @package geckon01\SimpleImageCompressor
+ */
+class SimpleImageCompressor
+{
+    private const ALLOWED_IMAGE_FORMAT = "image/jpeg,image/png,image/gif";
+    private string $imageResourceUrl;
+    private string $imageData;
+    private string $imageType;
+
+    private int $approxMinimumHeight = 90;
+    private int $approxMinimumWidth = 90;
+
+    /**
+     * SimpleImageCompressor constructor.
+     * @param $url
+     */
+    private function __construct($url)
+    {
+        $this->imageResourceUrl = $url;
+    }
+
+    /**
+     * Returns current loaded image type
+     * @return string
+     */
+    public function getImageType(): string
+    {
+        return $this->imageType;
+    }
+
+    /**
+     * @return int
+     */
+    public function getApproxMinimumHeight(): int
+    {
+        return $this->approxMinimumHeight;
+    }
+
+    /**
+     * @return int
+     */
+    public function getApproxMinimumWidth(): int
+    {
+        return $this->approxMinimumWidth;
+    }
+
+    /**
+     * @param int $approxMinimumHeight
+     */
+    public function setApproxMinimumHeight(int $approxMinimumHeight): SimpleImageCompressor
+    {
+        $this->approxMinimumHeight = $approxMinimumHeight;
+        return $this;
+    }
+
+    /**
+     * @param int $approxMinimumWidth
+     */
+    public function setApproxMinimumWidth(int $approxMinimumWidth): SimpleImageCompressor
+    {
+        $this->approxMinimumWidth = $approxMinimumWidth;
+        return $this;
+    }
+
+    /**
+     * Determine current loaded image type
+     */
+    private function loadImageType() {
+        $filetype = '';
+
+        if (substr($this->imageData, 0, 2) === "\xFF\xD8") {
+            $filetype = 'image/jpeg';
+        } elseif (substr($this->imageData, 0, 3) === "\x89\x50\x4E") {
+            $filetype = 'image/png';
+        } elseif (substr($this->imageData, 0, 4) === "\x47\x49\x46\x38") {
+            $filetype = 'image/gif';
+        }
+
+        $this->imageType = $filetype;
+    }
+
+    /**
+     * Loading image from provided url. Whether it local file or internet resource
+     */
+    private function readImageToString(): void {
+        $imageData = file_get_contents($this->imageResourceUrl);
+        $this->imageData = $imageData;
+    }
+
+    /**
+     * Resizes and compressing image.
+     * Note that gif compression not supported
+     * @param int $resolutionReductionPercent percent shows how much image resolution to original will be. The greater percent, the lower resolution
+     * @param int $quality
+     * @return CompressedImage
+     */
+    public function resizeAndCompress($resolutionReductionPercent = 5, $quality = 90): CompressedImage
+    {
+        $im = imagecreatefromstring($this->imageData);
+        $width = imagesx($im);
+        $height = imagesy($im);
+
+        $totalPixelCount = $width * $height;
+        $minimumPixelCount = $this->approxMinimumWidth * $this->approxMinimumHeight;
+        $maximumResolutionReductionPercent = round(abs(100 - ($minimumPixelCount / $totalPixelCount * 100)));
+
+        //Due to saving proportion we can't guarantee that width and height be equals max and min
+        //As example, if we have original image 1920*1080 which we want to get 50% of original resolution
+        //If we want to save 16*9 aspect ration it must be 960*540
+        //So, we override $maximumResolutionReductionPercent to value which satisfy origin aspect ratio
+        if($maximumResolutionReductionPercent < $resolutionReductionPercent)
+            $resolutionReductionPercent = $maximumResolutionReductionPercent;
+
+        $newWidth = round($width - ($width * $resolutionReductionPercent) / 100);
+        $newHeight = round($height - ($height * $resolutionReductionPercent) / 100);
+
+        $thumb = imagecreatetruecolor($newWidth, $newHeight);
+        imagecopyresized($thumb, $im, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
+
+        return new CompressedImage($quality, $this->imageType,$thumb);
+    }
+
+    /**
+     * Initalize lib from provided image file path
+     * @param string $urlImageResource image resource path. Can be local file or internet URL
+     * @return SimpleImageCompressor
+     * @throws \Exception
+     */
+    public static function load(string $urlImageResource): SimpleImageCompressor
+    {
+        $compressorObject = new SimpleImageCompressor($urlImageResource);
+        $compressorObject->readImageToString();
+        $compressorObject->loadImageType();
+
+        if(!str_contains(self::ALLOWED_IMAGE_FORMAT, $compressorObject->getImageType())
+            || $compressorObject->getImageType() === "")
+            throw new \Exception("Provided file resource must contain one of image mime types: ".self::ALLOWED_IMAGE_FORMAT);
+
+        return $compressorObject;
+    }
+}