Abstract: A guidance control device is configured to control a projection device for projecting images. The guidance control device is configured to generate a subject-identifying image to be projected on a first projection range relating to a first position at which a subject person conducts a predetermined operation and to generate a guide image guiding the predetermined operation for the subject person to be projected on a second projection range relating to a second position viewable by the subject person. Accordingly, the guidance control device is able to control the projection device including the subject-identifying image and the guide image.

Abstract: The DC level of the low-frequency component of a horizontal frequency is detected from a video signal by a horizontal low pass filter (LPF) 16d and a DC value detection circuit. In addition, the high-frequency component of the horizontal frequency is detected from the video signal by a horizontal band pass filter (BPF) and a nonlinear circuit. Furthermore, a high-frequency component in the vertical direction is detected from the video signal by a vertical BPF 16i and a nonlinear circuit 16i. On the basis of three detection results, the presence/absence of a non-image portion of the video signal is determined by a determination circuit.

Abstract: The DC level of the low-frequency component of a horizontal frequency is detected from a video signal by a horizontal LPF 16d and a DC value detection circuit 16g. In addition, the high-frequency component of the horizontal frequency is detected from the video signal by a horizontal BPF 16e and a nonlinear circuit 16h. Furthermore, a high-frequency component in the vertical direction is detected from the video signal by a vertical BPF 16f and a nonlinear circuit 16i. On the basis of three detection results, the presence/absence of a non-image portion of the video signal is determined by a determination circuit 16j.