Image mode application method and surveillance apparatus

An image mode application method applied to a surveillance apparatus with an operation processor, the operation processor receiving an image stream having a first detection image and a second detection image generated in sequence, the image mode application method comprising:

• the operation processor detecting a first feature of a first target object within the first detection image;
• the operation processor switching an application mode of the surveillance apparatus from a first mode to a second mode in accordance with a detection result of the first feature;
• the operation processor detecting a second feature of the first target object within the second detection image;
• the operation processor determining whether the second feature conforms to the first feature;
• and
• the operation processor switching the application mode from the second mode to the first mode when the second features conforms to the first feature.