Method for processing display of multi-layer picture in picture for DLP multi-screen splicing display wall

The invention relates to a method for processing display of multi-layer picture in picture for a DLP (digital light processing) multi-screen tiled display wall. The method adopts the ASIC chip multi-picture roaming technology, ensures that a projection unit can simultaneously drive 3 full real-time RGB and video signal images, and comprises the following steps: inputting an external signal which comprises a main picture signal and a sub-picture signal; converting all signals through an analog to digital converter; performing filter correction to the converted signals by a signal filter correction circuit; allowing the processed sub-image signal through a sub-image signal adjusting circuit; leading the adjusted sub-image signal to enter a sub-image switching circuit; forming a sub-picture image by a sub-picture forming circuit; and synthesizing a main picture image and a sub- picture image by a picture synthesis circuit, and displaying the images on a large screen. Compared with the prior art, the method has t