Full-screen display method, related devices, and systems for upright image

A full-screen display method for upright images, the mirroring same-screen device comprises a receiving end and a transmitting end to receive the vertical screen's first displayed image;

• the display device includes a video input end that is connected to the transmitting end;
• the mirroring same-screen device generates the second image in landscape mode by processing the first image's data and then transmits the second image to the video input end using the transmitting end in order to show it on the display device;
• the full-screen display method of an upright image is applied to the transmitting end or the video input end, and the method comprises the following steps:
• reading the resolution of the second image and the resolution of the said second image is a:b, wherein a is the horizontal pixel scaling factor of the second image and b is the vertical pixel scaling factor of the second image;
• extracting from the second image to generate the third image and the resolution of the third image is b:a, wherein b is the horizontal pixel scaling factor of the third image and a is the vertical pixel scaling factor of the third image, the center line of the second image and of the third image coincide in both the horizontal and vertical directions, and the number of pixels of the second image in the vertical direction is the same as that of the third image in the vertical direction;
• rotating the third image by 90 degrees along the set direction to generate the fourth image;
• and
• displaying the fourth image full-screen and in portrait mode on the display device;
• wherein the extraction is taking the center line of the second image as that of the third image and intercepting the image with resolution of x:b;
• wherein x is the horizontal pixel scaling factor, b is the vertical pixel scaling factor, and x satisfies the following formula:
• x
• =
• b
• 2
• a
• .