feature: add a setting to use 'imagecopyresampled' instead of 'imagec…

…opyresized'

This function provides a better rendering after resizing with a tradoff of a higher CPU usage.
resampling is now used by default and can be changed using a simple setting before retrieving thumbnails.

The cache is not invalidated automatically by this option.

README.md

@@ -142,7 +142,35 @@ Usage:
 $wt = $wt->crop(true);
 $conf = [WebThumbnailer::CROP => true];
 ```
+
+### Resize Mode
+
+This setting choose whether to use `imagecopyresized` (RESIZE mode) or `imagecopyresampled` (RESAMPLE mode):
+
+  * `RESAMPLE`: higher CPI usage, with better resized image rendering.
+  * `RESIZE`: faster and lower CPU usage, but the resized image might not look as good.
 
+By default, this library uses `RESAMPLE` setting since the setting was introduced.
+
+Example:
+
+|---------------------RESIZE---------------------|---------------------RESAMPLE---------------------|
+
+![](https://user-images.githubusercontent.com/28786873/195634626-ec80e2ac-43f1-4f00-a507-8ba30dc5dda7.jpg)
+![](https://user-images.githubusercontent.com/28786873/195634635-87f84476-e923-461c-accf-d3e5988e33a5.jpg)
+
+Usage:
+
+```php
+// Resize
+$wt = $wt->resize();
+$conf = [WebThumbnailer::RESIZE_MODE => WebThumbnailer::RESIZE];
+
+// Resample
+$wt = $wt->resample();
+$conf = [WebThumbnailer::RESIZE_MODE => WebThumbnailer::RESAMPLE];
+```
+
 ### Miscellaneous
 
   * **NOCACHE**: Force the thumbnail to be resolved and downloaded instead of using cache files.

src/Application/Thumbnailer.php

@@ -55,7 +55,7 @@ class Thumbnailer
     public function __construct(string $url, array $options, ?array $server)
     {
         ApplicationUtils::checkExtensionRequirements(['gd']);
-        ApplicationUtils::checkPHPVersion('5.6', PHP_VERSION);
+        ApplicationUtils::checkPHPVersion('7.1', PHP_VERSION);
 
         $this->url = $url;
         $this->server = $server;
@@ -128,6 +128,13 @@ protected function setOptions(array $options): void
             $this->options[WebThumbnailer::DEBUG] = false;
         }
 
+        // Resize mode, defaults to resample
+        if (isset($options[WebThumbnailer::RESIZE_MODE])) {
+            $this->options[WebThumbnailer::RESIZE_MODE] = $options[WebThumbnailer::RESIZE_MODE];
+        } else {
+            $this->options[WebThumbnailer::RESIZE_MODE] = WebThumbnailer::RESAMPLE;
+        }
+
         // Image size
         $this->setSizeOptions($options);
     }
@@ -354,7 +361,8 @@ protected function thumbnailDownload(string $thumbUrl)
             $thumbPath,
             $this->options[WebThumbnailer::MAX_WIDTH],
             $this->options[WebThumbnailer::MAX_HEIGHT],
-            $this->options[WebThumbnailer::CROP]
+            $this->options[WebThumbnailer::CROP],
+            $this->options[WebThumbnailer::RESIZE_MODE]
         );
 
         if (!is_file($thumbPath)) {

src/Utils/ImageUtils.php

@@ -6,6 +6,7 @@
 
 use WebThumbnailer\Exception\ImageConvertException;
 use WebThumbnailer\Exception\NotAnImageException;
+use WebThumbnailer\WebThumbnailer;
 
 /**
  * Util class to manipulate GD images.
@@ -33,7 +34,8 @@ public static function generateThumbnail(
         string $target,
         int $maxWidth,
         int $maxHeight,
-        bool $crop = false
+        bool $crop = false,
+        string $resizeMode = WebThumbnailer::RESAMPLE
     ): void {
         if (!touch($target)) {
             throw new ImageConvertException('Target file is not writable.');
@@ -74,8 +76,9 @@ public static function generateThumbnail(
             throw new ImageConvertException('Could not generate the thumbnail from source image.');
         }
 
+        $resizeFunction = $resizeMode === WebThumbnailer::RESIZE ? 'imagecopyresized' : 'imagecopyresampled';
         if (
-            !imagecopyresized(
+            !$resizeFunction(
                 $targetImg,
                 $sourceImg,
                 0,

src/WebThumbnailer.php

@@ -52,6 +52,15 @@ class WebThumbnailer
     /** Debug mode. Throw exceptions. */
     public const DEBUG = 'DEBUG';
 
+    /** Setting to define resize mode */
+    public const RESIZE_MODE = 'RESIZE_MODE';
+
+    /** Resize mode: less CPU usage but could end up pixellized */
+    public const RESIZE = 'RESIZE';
+
+    /** Resample mode: more CPU usage but smoother rendering */
+    public const RESAMPLE = 'RESAMPLE';
+
     /** @var int|null */
     protected $maxWidth = null;
 
@@ -79,6 +88,9 @@ class WebThumbnailer
     /** @var string|null */
     protected $downloadMode = null;
 
+    /** @var string|null */
+    protected $resizeMode = null;
+
     /**
      * Get the thumbnail for the given URL>
      *
@@ -106,6 +118,7 @@ public function thumbnail(string $url, array $options = [])
                 static::DOWNLOAD_TIMEOUT => $this->downloadTimeout,
                 static::DOWNLOAD_MAX_SIZE => $this->downloadMaxSize,
                 static::CROP => $this->crop,
+                static::RESIZE_MODE => $this->resizeMode,
                 $this->downloadMode
             ],
             $options
@@ -262,4 +275,30 @@ public function modeHotlinkStrict(): self
 
         return $this;
     }
+
+    /**
+     * Apply resize mode during resizing:
+     * lower CPU usage but sometimes rougher rendering.
+     *
+     * @return WebThumbnailer $this
+     */
+    public function resize(): self
+    {
+        $this->resizeMode = static::RESIZE;
+
+        return $this;
+    }
+
+    /**
+     * Apply resample mode during resizing:
+     * slightly more CPU usage but smoother rendering.
+     *
+     * @return WebThumbnailer $this
+     */
+    public function resample(): self
+    {
+        $this->resizeMode = static::RESAMPLE;
+
+        return $this;
+    }
 }

tests/WebThumbnailerTest.php

@@ -90,14 +90,28 @@ public function testDirectImageWithoutExtension(): void
     /**
      * URL which contains an opengraph image.
      */
-    public function testOpenGraphImage(): void
+    public function testOpenGraphImageResample(): void
+    {
+        $image = 'default/le-monde-full.jpg';
+        $this->regenerate($image, true, [0, 0, 160, 80]);
+        $expected = self::$regenerated . $image;
+        $url = self::LOCAL_SERVER . 'default/le-monde.html';
+        $wt = new WebThumbnailer();
+        $thumb = $wt->resample()->thumbnail($url);
+        $this->assertFileEquals($expected, $thumb);
+    }
+
+    /**
+     * URL which contains an opengraph image.
+     */
+    public function testOpenGraphImageResize(): void
     {
         $image = 'default/le-monde.jpg';
-        $this->regenerate($image);
+        $this->regenerate($image, false, [], 'imagecopyresized');
         $expected = self::$regenerated . $image;
         $url = self::LOCAL_SERVER . 'default/le-monde.html';
         $wt = new WebThumbnailer();
-        $thumb = $wt->thumbnail($url);
+        $thumb = $wt->resize()->thumbnail($url);
         $this->assertFileEquals($expected, $thumb);
     }
 
@@ -243,11 +257,11 @@ public function testDownloadDirectImageResizeHeightCrop(): void
     public function testDownloadDirectImageResizeWidthHeightCrop(): void
     {
         $image = 'default/image-crop-341-341.png';
-        $this->regenerate($image, true);
+        $this->regenerate($image, true, [], 'imagecopyresized');
         $expected = self::$regenerated . $image;
         $url = self::LOCAL_SERVER . 'default/image-crop.png';
         $wt = new WebThumbnailer();
-        $wt = $wt->maxHeight(341)->maxWidth(341)->crop(true);
+        $wt = $wt->maxHeight(341)->maxWidth(341)->resize()->crop(true);
         $thumb = $wt->thumbnail($url);
         $this->assertEquals(base64_encode(file_get_contents($expected)), base64_encode(file_get_contents($thumb)));
         $this->assertFileEquals($expected, $thumb);
@@ -260,11 +274,11 @@ public function testDownloadDirectImageResizeWidthHeightCrop(): void
     public function testDownloadDirectImageResizeWidthHeightCropOverride(): void
     {
         $image = 'default/image-crop-120-160.png';
-        $this->regenerate($image, true);
+        $this->regenerate($image, true, [], 'imagecopyresized');
         $expected = self::$regenerated . $image;
         $url = self::LOCAL_SERVER . 'default/image-crop.png';
         $wt = new WebThumbnailer();
-        $wt = $wt->maxHeight(341)->maxWidth(341)->crop(true);
+        $wt = $wt->maxHeight(341)->maxWidth(341)->crop(true)->resize();
         $thumb = $wt->thumbnail(
             $url,
             [
@@ -336,8 +350,12 @@ public function testHotlinkOpenGraphJsonConfig(): void
      *
      * @throws \Exception couldn't create the image.
      */
-    public function regenerate(string $image, bool $crop = false, array $cropParameters = []): void
-    {
+    public function regenerate(
+        string $image,
+        bool $crop = false,
+        array $cropParameters = [],
+        string $resizeFunc = 'imagecopyresampled'
+    ): void {
         $targetFolder = dirname(self::$regenerated . $image);
         if (! is_dir($targetFolder)) {
             mkdir($targetFolder, 0755, true);
@@ -350,15 +368,15 @@ public function regenerate(string $image, bool $crop = false, array $cropParamet
 
         $targetImg = imagecreatetruecolor($width, $height);
         if (
-            !imagecopyresized(
+            !$resizeFunc(
                 $targetImg,
                 $sourceImg,
                 0,
                 0,
                 0,
                 0,
-                $width,
-                $height,
+                $cropParameters[2] ?? $width,
+                $cropParameters[3] ?? $height,
                 $width,
                 $height
             )