Generally SharePoint content writers can get images from other departments like marketing or business development users in some high resolution formats. Content writers can upload that image to the SharePoint after re-sizing the image to their need. In SharePoint 2013 we are having the option to re size the image in site itself. We can re-size the image by using image rendition techniques in SharePoint. By using this we can add images to library and we can re size them in various sizes before adding them to pages.
To use image renditions we have to enable publishing feature and BLOB cache. We can turn on the BLOB cache in Web.config file. To enable blob cache, navigate IISManager and select site, explore to content view. Edit web.config file using any text editor. Search for “<BlobCache” tag, in the line we’ll see enabled=”false”. Change that to “true”, save the file.
By enabling the Publishing feature in Site collection we can “Image Renditions” link in “Look and Feel” section of Site Settings page.
By clicking on the Image Renditions link we’ll navigated to Image Renditions page. We can see default Display Templates with height and width. To create new layout, Click on “Add New Item” link and need to provide height and width.
To crop images, Navigate to picture library, select the image to crop and select “Edit Renditions” in top ribbon “Design” section.
We can see the image in the available Display Templates formats as shown below.
To use renditions, Add image to SharePoint publishing page and Select “IMAGE” on the top ribbon, click on “Pick Renditions” button on top ribbon. We can select the template as our requirement.