Best Way to Trigger and Download Images from Canon Cameras via USB?

I explored several methods to trigger a 35mm camera connected via USB:

1- ICCameraDevice: Unable to make it work with Canon cameras (details).

2- Canon's EDSDK: Works but is complex to implement.

3- gPhoto2 (command-line): Simple to use but requires gPhoto2 to be installed.

In your opinion, what is the most efficient way to trigger and download images via USB from Canon cameras?

Best Way to Trigger and Download Images from Canon Cameras via USB?
 
 
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