Continuous focusing method for digital camera

A continuous focusing method for a digital camera, applicable to determine whether the digital camera performs a continuous focusing procedure or not when the digital camera switches from a first scene to a second scene in a live view stage, the continuous focusing method comprising:

• obtaining a preview image at the second scene;
• performing a blur detection procedure on the preview image to acquire a focus value, wherein the blur detection procedure comprises:
• setting at least one sampling area in the preview image, wherein the sampling area has a plurality of image pixels;
• comparing pixel values of every two adjacent image pixels in the sampling area respectively to obtain a plurality of contrast differences;
• and
• accumulating a number of the contrast differences greater than a preset threshold value as the focus value;
• determining whether the focus value exceeds a focusing threshold value or not;
• and
• if not, performing the continuous focusing procedure.