If your SD memory card not reading your images then it might be possible that it has been corrupted. It sometimes gives to photo loss situations. In order to resolve this problem you need to format your SD card and then restore lost images using Foto Recovery Software. It is powerful software that safely restores your lost images of any formats.
The software is developed with latest techniques which is capable to recover deleted, lost or inaccessible images form corrupt memory cards. It also supports recovery from hard drive, memory stick, USB drive etc. So, you can use this effective software to get back your lost images of SD card.
IF you are still not able to resolve your problem then you can try formatting your camera. If it still doesn't help then read the following informative articles related to different camera and card errors. Hope it might helps. http://digital-photo-recovery-software.blogspot.com/