The ThumbnailService component is used to resize all the images into different sizes. Besides the default sizes, it also allows users to customize the images into the desired sizes.
The configuration of this component is found in  _/core/core-configuration/src/main/webapp/WEB-INF/conf/wcm-core/core-services-configuration.xml_.
{code}
<component>
	  <key>org.exoplatform.services.cms.thumbnail.ThumbnailService</key>
	  <type>org.exoplatform.services.cms.thumbnail.impl.ThumbnailServiceImpl</type>
	  <init-params>
      <value-param>
      	<name>smallSize</name>
	      <value>32x32</value>
      </value-param>
      <value-param>
      	<name>mediumSize</name>
	      <value>64x64</value>
      </value-param>
      <value-param>
      	<name>largeSize</name>
	      <value>300x300</value>
      </value-param>
      <value-param>
      	<name>enable</name>
	      <value>false</value>
      </value-param>
      <value-param>
        <name>mimetypes</name>
        <value>image/jpeg;image/png;image/gif;image/bmp</value>
      </value-param>
    </init-params>
</component>
{code}

*Details*:
||Value-param|| Possible value || Default value || Description ||
|*smallSize* |32x32|32x32| The small thumbnail size.|
|*mediumSiz* |64x64|64x64|The medium thumbnail size.|
|*largeSize* |300x300|300x300|The large thumbnail size.|
|*enable* |boolean|false|Specify if the thumbnail is displayed or not.|
|*mimetypes* |images formats|image/jpeg;image/png;image/gif;image/bmp|The image formats are supported.|
