Thumbnail location of Images/Videos in sdcard

I would like to know the location of the stored thumbnails in android sdcard. I used the adb push service to upload images and videos to the sdcard. But even after deleting few images, my application is loading the thumbnails of the deleted images which is creating problems. When I click the thumbnails, instead of the corresponding image, some other image is opening. How to delete/ re-populate the thumbnails? Also How to load the original image of the clicked thumbnail? How does android retrieve the original image corresponding to its thumbnail? what's th开发者_开发知识库e mapping between these two?

Thanks in advance.

Well, if you are are using system intents, like ACTION_PICK, then you probably need run media scanner ( Applications > Dev Tools > Media Scanner )