This document basically explains how to change the branding image/branding text which appears in the /irj portal logon page.
In order to decide the path from which these images are taken, please perform the following steps
2. Do not login.
3. Right click the image in the logon page and check the properties, this will provide the information of where the image is taken from as well as pixel size
4. You should find something like this
Address : https://<hostname:port>/irj/portalapps/com.sap.portal.runtime.logon/layout/branding-image.jpg
5. The information above basically tell us where this image is called from. So this image was called from
6. Replace the SAP image with customized image for all the server nodes, pixel size information can be obtained from looking at the properties as mentioned in step 3
7. Usually if you replace the branding image it doesn't require a restart, but for branding text it does require a restart