Add setScreenshotType() method + Update Readme

README.md

@@ -141,9 +141,19 @@ Here's the easiest way to create an image of a webpage:
 Browsershot::url('https://example.com')->save($pathToImage);
 ```
 
+#### Formatting the image
+By default the screenshot's type will be a `png`. (According to [Puppeteer's Config](https://github.com/GoogleChrome/puppeteer/blob/master/docs/api.md#pagescreenshotoptions))  
+But you can change it to `jpeg` with quality option.
+
+```php
+Browsershot::url('https://example.com')
+    ->setScreenshotType('jpeg', 100)
+    ->save($pathToImage);
+```
+
 #### Sizing the image
 
-By default the screenshot will be a `png` and it's size will match the resolution you use for your desktop. Want another size of screenshot? No problem!
+By default the screenshot's size will match the resolution you use for your desktop. Want another size of screenshot? No problem!
 
 ```php
 Browsershot::url('https://example.com')
@@ -402,7 +412,7 @@ Browsershot::url('https://example.com')
 #### Changing the language of the browser
 
 You can use `setOption` to change the language of the browser.  
-In order to load a page in a specific language for example. 
+In order to load a page in a specific language for example.
 
 ```php
 Browsershot::url('https://example.com')

src/Browsershot.php

@@ -23,6 +23,8 @@ class Browsershot
     protected $proxyServer = '';
     protected $showBackground = false;
     protected $showScreenshotBackground = true;
+    protected $screenshotType = 'png';
+    protected $screenshotQuality = null;
     protected $temporaryHtmlDirectory;
     protected $timeout = 60;
     protected $url = '';
@@ -218,6 +220,17 @@ public function hideBackground()
         return $this;
     }
 
+    public function setScreenshotType(string $type, int $quality = null)
+    {
+        $this->screenshotType = $type;
+
+        if (! is_null($quality)) {
+            $this->screenshotQuality = $quality;
+        }
+
+        return $this;
+    }
+
     public function ignoreHttpsErrors()
     {
         return $this->setOption('ignoreHttpsErrors', true);
@@ -408,11 +421,18 @@ public function createScreenshotCommand($targetPath = null): array
     {
         $url = $this->html ? $this->createTemporaryHtmlFile() : $this->url;
 
-        $options = [];
+        $options = [
+            'type' => $this->screenshotType,
+        ];
+
         if ($targetPath) {
             $options['path'] = $targetPath;
         }
 
+        if ($this->screenshotQuality) {
+            $options['quality'] = $this->screenshotQuality;
+        }
+
         $command = $this->createCommand($url, 'screenshot', $options);
 
         if (! $this->showScreenshotBackground) {