Printing system, control method therefor, and photo-direct printing apparatus

A printing system in which an image supply device and a printing apparatus are directly connected via a general-purpose interface, and image data is transmitted from the image supply device to the printing apparatus and printed, the system comprising:

• transmission means for transmitting function information of the printing apparatus from the printing apparatus to the image supply device after establishing a communication procedure by an application installed in the printing apparatus and the image supply device;
• and
• means for causing the printing apparatus to execute print operation in accordance with a print condition set by the image supply device on the basis of the function information transmitted by said transmission means.