Gregwar
diff --git a/Converter.php b/Converter.php
@@ -0,0 +1,60 @@
+<?php
+/**
+ * Converter resource
+ * User: Clem
+ * Date: 30/05/2019
+ * Time: 21:46
+ */
+
+namespace Gregwar\Image;
+
+class Converter
+{
+
+  /**
+   * Convert Cm to Pixels using resolution in DPI
+   * @param float $cm
+   * @param int $resolution in DPI (PPP)
+   * @return float
+   */
+  static function cmToPixels($cm, $resolution = 96) {
+    return $resolution * $cm / 2.54;
+  }
+
+  /**
+   * Convert Inch to Pixels using resolution in DPI
+   * @param float $inch
+   * @param int $resolution in DPI (PPP)
+   * @return float
+   */
+  static function inchToPixels($inch, $resolution = 96) {
+    return $resolution * $inch;
+  }
+
+  /**
+   * Convert Pixels to Cm using resolution in DPI
+   * @param int $pixels
+   * @param int $resolution in DPI (PPP)
+   * @return float|int|boolean
+   */
+  static function pixelsToCm($pixels, $resolution = 96) {
+    if($resolution == 0) {
+      return false;
+    }
+    return $pixels * 2.54 / $resolution;
+  }
+
+  /**
+   * Convert Pixels to Inch using resolution in DPI
+   * @param int $pixels
+   * @param int $resolution in DPI (PPP)
+   * @return float|boolean
+   */
+  static function pixelsToInch($pixels, $resolution = 96) {
+    if($resolution == 0) {
+      return false;
+    }
+    return $pixels / $resolution;
+  }
+
+}
diff --git a/Image.php b/Image.php
@@ -756,6 +756,22 @@ public function inline($type = 'jpg', $quality = 80)
         return 'data:image/'.$mime.';base64,'.base64_encode(file_get_contents($this->cacheFile($type, $quality, true)));
     }
 
+  /**
+   * Return the resolution of resource
+   * @param string $type
+   * @return array|bool|mixed
+   */
+    public function getResolution($type = 'both')
+    {
+      if(function_exists('imageresolution')) {
+        $res = imageresolution ($this->getAdapter()->getResource());
+        if(is_array($res)) {
+          return ($type === 'both') ? $res : (($type === 'Y') ? $res[1] : $res[0]);
+        }
+      }
+      return false;
+    }
+
     /**
      * Creates an instance, usefull for one-line chaining.
      */

diff --git a/README.md b/README.md
@@ -117,6 +117,8 @@ The other methods available are:
 
 * `inline($type = 'jpg')`: returns the HTML inlinable base64 string (see `demo/inline.php`)
 
+* `getResolution($type = 'both')`: returns the resolution of picture in DPI. Only available for >= PHP 7. Other $type options: `X` for horizontal resolution, `Y` for vertical resolution, `both` for the both.
+
 You can also create image from scratch using:
 
 ```php
@@ -138,6 +140,20 @@ You can save the image to an explicit file using `save($file, $type = 'jpg', $qu
 
 You can also get the contents of the image using `get($type = 'jpg', $quality = 80)`, which will return the binary contents of the image
 
+## Converter
+
+Converter allow you to convert centimeters to pixels, inch to pixels... using defined resolution in DPI.
+
+The following static method are available:
+
+* `cmToPixels($cm, $resolution = 96)`: convert centimeters to pixels.
+
+* `inchToPixels($cm, $resolution = 96)`: convert inch to pixels.
+
+* `pixelsToCm($cm, $resolution = 96)`: convert pixels to centimeters.
+
+* `pixelsToInch($cm, $resolution = 96)`: convert pixels to inch.
+
 ## Using cache
 
 Each operation above is not actually applied on the opened image, but added in an operations

diff --git a/composer.json b/composer.json
@@ -28,5 +28,8 @@
         "psr-0": {
             "Gregwar\\Image": ""
         }
+    },
+    "scripts": {
+        "test": "simple-phpunit --bootstrap vendor/autoload.php"
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
@@ -15,6 +15,9 @@
         <testsuite name="Image testing">
             <file>./tests/ImageTests.php</file>
         </testsuite>
+        <testsuite name="Converter testing">
+            <file>./tests/ConverterTests.php</file>
+        </testsuite>
     </testsuites>
 
 </phpunit>
diff --git a/tests/ConverterTests.php b/tests/ConverterTests.php
@@ -0,0 +1,66 @@
+<?php
+/**
+ * Tests for Converter class
+ * User: Clem
+ * Date: 31/05/2019
+ * Time: 09:39
+ */
+
+use \Gregwar\Image\Converter;
+
+class ConverterTests extends \PHPUnit\Framework\TestCase
+{
+  public function testCmToPixels()
+  {
+    // Basic convertion
+    $this->assertEquals(37.795275591, Converter::cmToPixels(1), '', 0.001);
+
+    // 6cm convertion
+    $this->assertEquals(226.771653543, Converter::cmToPixels(6), '', 0.001);
+
+    // 6cm convertion with 300 dpi
+    $this->assertEquals(708.6614173, Converter::cmToPixels(6, 300), '', 0.001);
+  }
+
+  public function testInchToPixels()
+  {
+    // Basic convertion
+    $this->assertEquals(96, Converter::inchToPixels(1));
+
+    // 6inch convertion
+    $this->assertEquals(576, Converter::inchToPixels(6));
+
+    // 6inch convertion with 300 dpi
+    $this->assertEquals(1800, Converter::inchToPixels(6, 300));
+  }
+
+  public function testPixelsToCm()
+  {
+    // Basic convertion
+    $this->assertEquals(0.026458333, Converter::pixelsToCm(1), '', 0.001);
+
+    // 960 pixels convertion
+    $this->assertEquals(25.4, Converter::pixelsToCm(960), '', 0.001);
+
+    // 960 pixels with 300 dpi
+    $this->assertEquals(8.128, Converter::pixelsToCm(960, 300), '', 0.001);
+
+    // 960 pixels with 0 dpi
+    $this->assertEquals(false, Converter::pixelsToCm(960, 0));
+  }
+
+  public function testPixelsToInch()
+  {
+    // Basic convertion
+    $this->assertEquals(0.010416667, Converter::pixelsToInch(1), '', 0.001);
+
+    // 960 pixels convertion
+    $this->assertEquals(10, Converter::pixelsToInch(960), '', 0.001);
+
+    // 960 pixels with 300 dpi
+    $this->assertEquals(3.2, Converter::pixelsToInch(960, 300), '', 0.001);
+
+    // 960 pixels with 0 dpi
+    $this->assertEquals(false, Converter::pixelsToInch(960, 0));
+  }
+}