diff --git a/app/Http/Controllers/UploadController.php b/app/Http/Controllers/UploadController.php
index 92ded82..8b57543 100644
--- a/app/Http/Controllers/UploadController.php
+++ b/app/Http/Controllers/UploadController.php
@@ -161,7 +161,7 @@ class UploadController extends Controller {
 						   }
 
 							$resolutions = $im->getImageResolution();
-							$media->resolution = round($resolutions['x'] * 2.54, 2);
+							$media->resolution = round($resolutions['x'] * 2.54);
 							$imageprops = $im->getImageGeometry();
 							$media->largeur = $imageprops['width'];
 							$media->hauteur = $imageprops['height'];
diff --git a/app/Http/Traits/MediaTools.php b/app/Http/Traits/MediaTools.php
index 42415eb..baabd2e 100644
--- a/app/Http/Traits/MediaTools.php
+++ b/app/Http/Traits/MediaTools.php
@@ -1,5 +1,6 @@
 <?php
 namespace App\Http\Traits;
+use App\Models\Format;
 use Illuminate\Support\Facades\Storage;
 
 trait MediaTools {
@@ -58,32 +59,36 @@ trait MediaTools {
         }*/
 
 		// create preview
+        $format = Format::withoutGlobalScope('App\Scopes\SystemScope')->where('libelle', '=', 'preview')->first();
 		$fp = public_path()."/".$media->folder.$media->uid.'_preview.'.$extension;
 		if($media->extension == "gif" ){
-			if($media->largeur >= 1500 || $media->hauteur >= 1500 || $media->largeur == ""){
+			if($media->largeur >= $format->largeur || $media->hauteur >= $format->hauteur || $media->largeur == ""){
 				$im = $im->coalesceImages();
 				foreach ($im as $frame) {
-				  $frame->thumbnailImage(1500, 1500);
-				  $frame->setImagePage(1500, 1500, 0, 0);
+				  $frame->thumbnailImage($format->largeur, $format->hauteur);
+				  $frame->setImagePage($format->largeur, $format->hauteur, 0, 0);
 				}
 				$im = $im->deconstructImages();
 			}
 			$im->writeImages($fp, true);
 		}else{
-			if($media->largeur >= 1500 || $media->hauteur >= 1500 || $media->largeur == ""){
-				$im->thumbnailImage(1500, 1500 , true);
+			if($media->largeur >= $format->largeur || $media->hauteur >= $format->hauteur || $media->largeur == ""){
+				$im->thumbnailImage($format->largeur, $format->hauteur , true);
 			}
 			$im->writeImage($fp);
 		}
 
 
 		// create thumb
-		$im->setImageBackgroundColor('#ffffff');
-		$im->setImageAlphaChannel(\Imagick::ALPHACHANNEL_REMOVE);
-		$im->mergeImageLayers(\Imagick::LAYERMETHOD_FLATTEN);
-		$im->stripImage();
+        $format = Format::withoutGlobalScope('App\Scopes\SystemScope')->where('libelle', '=', 'thumb')->first();
+		if ($extension != "png"){
+            $im->setImageBackgroundColor('#ffffff');
+            $im->setImageAlphaChannel(\Imagick::ALPHACHANNEL_REMOVE);
+            $im->mergeImageLayers(\Imagick::LAYERMETHOD_FLATTEN);
+            $im->stripImage();
+        }
 		$fp = public_path()."/".$media->folder.$media->uid.'_thumb.'.$extension;
-		$im->thumbnailImage(200, 200 , true);
+		$im->thumbnailImage($format->largeur,  $format->hauteur , true);
 		$im->writeImage($fp);
 		$im->destroy();
         unset($im);
diff --git a/resources/views/layouts/media_edit.blade.php b/resources/views/layouts/media_edit.blade.php
index 25bb92e..68cb3fc 100644
--- a/resources/views/layouts/media_edit.blade.php
+++ b/resources/views/layouts/media_edit.blade.php
@@ -212,7 +212,7 @@
 								<input type="text" id="hauteur" name="hauteur" readonly >
 							</div>
 							<div class="row">
-								<label for="resolution">Résolution</label>
+								<label for="resolution">Résolution (dpi)</label>
 								<input type="text" id="resolution" name="resolution" readonly >
 							</div>
 							<div class="row">