So essentially the question you are asking is now about the serial camera output - I have no idea !!
If you look at the developers guide, https://www.ghielectronics.com/docs/176/serial-camera-module, you’ll find the code example creates a bitmap object the size of the screen, starts streaming, then calls DrawImage to map the image into the bitmap. If you look at the product guide https://www.ghielectronics.com/catalog/product/382 it says JPEG, but I am not sure what method you’re meant to use to access the raw JPEG image.
You can see from the code for the driver, http://gadgeteer.codeplex.com/SourceControl/latest#Main/Modules/GHIElectronics/SerCam/Software/SerCam/SerCam_42/SerCam_42.cs that you also have some other functions that there are other image related public methods such as ReadFrameBuffer() that you may be able to leverage, or even extend the driver, that might be a “cleaner” approach than streaming and using DrawImage - I’ll say it again, I don’t know what you’re meant to use to access the JPG itself.
To store the image in memory, you need to have memory. With a Cobra you have plenty and shouldn’t have a problem with keeping an image in memory and then sending it out to the web response.
Hope that helps - sorry I don’t have a sercam module to actually help more and try it.
From a web perspective, I think you’re on the right path by creating a web page that contains an embedded image whose path is known (http://your.ip.address.here/sercam_image.jpg might be a good example) that in your server you then return the jpg data.