A non-transitory computer-readable storage medium having stored therein a program for causing a computer to implement a method of controlling an image processing apparatus that is connected with a scanner and issues a scanning instruction for causing the connected scanner to scan an image on a document based on a scan setting, the method comprising:
- notifying, by the controller of the image processing apparatus, the connected scanner of identification information of the image processing apparatus;
- and
- setting, by a scanner controller of the connected scanner, a clock frequency for transferring image data from the scanner controller to a controller of the image processing apparatus, based on the notified identification information;
- and
- determining, by the controller of the image processing apparatus, a timing of issuing a next scanning instruction for causing the scanner to scan an image on a next document based on the scan setting.