In a video monitoring system including HD and SD cameras, the system includes, on the transmitting side, a division/rotation processing unit for dividing an SD image into multiple divided images horizontally and performing a process for rotating the divided images by 90 degrees to the left, an image insertion unit for arranging and superimposing the divided images in a text telop region of an HD image, and a HD encoder for compressing and transmitting the HD image with the SD image superimposed. The system further includes, on the receiving side, a HD decoder for expanding the received HD image, and an output image processing unit for extracting the multiple divided images of the SD image and rotating these images by 90 degrees to the right, sorting and combining these images to reproduce the SD image, and outputting the expanded output HD image and the reproduced output SD image.