SharePoint 2013 Image Rendition Quality

Question

Is there any way to set the quality of the image rendition feature? By default it creates images with a low setting that produces a lot of compression artifacts.

Answer 1

I'm not completely sure what you mean by image rendition quality. If you mean compression quality I cannot help, but you can change the resolution using the SharePoint Design Manager.

1. Verify that the user account that is performing this procedure has, at minimum, Design permissions to the top-level site of the site collection.
2. In a browser, go to the top-level site of the publishing site collection.
3. Choose the Settings icon. On the Site Settings page, in the Look and Feel section, choose Image Renditions.
4. On the Image Renditions page, choose Add new item.
5. On the New Image Rendition page, in the Name box, enter a name for the rendition. For example, enter Thumbnail_Small.
6. In the Width and Height text boxes, enter the width and height, in pixels, of the rendition, and then choose Save.

http://msdn.microsoft.com/en-us/library/office/jj720398(v=office.15).aspx

EDIT:

I've done some research and it seems that there is no way to change the image encoding quality! Take a look at this MSDN thread: https://social.technet.microsoft.com/Forums/windows/en-US/da7ff7ca-0064-4ada-a6a5-d007b3714233/encoding-parameters-for-imagerenditions?forum=sharepointgeneral I think the only "solution" may be to supply a larger resolution and downscaling it with CSS.