How can I get a raw image from a consumer camera?
No, the camera is unlikely to expose the raw image at any point other than possibly the sensor connection to the DSP/MCU. The internal logic is likely to be highly integrated for cost reasons, using a custom ASIC to provide the processing functions.

Even what is saved as RAW will most likely have been processed and conditioned, this is simply the highest fidelity version of the image which is present in the processing path.

If the camera is able to stream data to a user connector, there might be test modes but I'm dubious about this. Even if they exist, accessing these test modes will be difficult. A USB remote-control interface is your best chance, if it is provided.