How do I get the actual image data from servlet.FileDownload?

Question

I'm using the rest api to query the data from an account: Account/001234abcde and images attached to the account are stored like this:

https://c.na20.content.force.com/servlet/servlet.FileDownload?file=00THEFILEID

I can see the image no problem from the browser if I'm currently authenticated in saleforce but the link does not work if I'm not authenticated and redirects me to the login page.

Is it possible to get the proper image data with the rest api without going through the above link? If not, how should images be uploaded to an account so that they can be retrieved easily using rest api?

Solution

Thanks to guy for the answer. Blob Retrieve is useful in this case. Here's the solution that I am using:

curl https://na1.salesforce.com/services/data/v20.0/sobjects/Attachment/00THEFILEID/body -H "Authorization: Bearer token"

Answer 1

Assuming that you are referring to Account record attachments..

First step will be to get the proper attachment id's. You can do that by querying the Account or the Attachment table, as described here https://stackoverflow.com/questions/13870089/how-to-display-salesforce-attachments-in-asp-net-website-to-download

Second step will be downloading the actual binary attachments. This can be done with the rest api's 'retrieve' command: http://www.salesforce.com/us/developer/docs/api_rest/index_Left.htm#CSHID=dome_sobject_blob_retrieve.htm|StartTopic=Content%2Fdome_sobject_blob_retrieve.htm|SkinName=webhelp

Or by decoding the 'body' field as also described in Eyescream's post (the first link)