Dual-screen assistive display methods and devices suitable for people with low vision and apparatuses

A dual-screen assistive display device-suitable for people with less than half their vision, comprising:

• a position information determination unit configured to determine position information of a microscopic region virtual frame referenced to a display image on a primary screen based on zoomLevel selected by a user, wherein the zoomLevel is a current microscopic control magnification level, the position information includes starting coordinates (Zoomx, Zoomy) and dimensions (Zoomw,Zoomh) of the microscopic region virtual frame;
• a position information mapping unit configured to map, based on a display parameter of the primary screen and a resolution W0×H0 of the display image on the primary screen, the position information of the microscopic region virtual frame to position information of a microscopic highlight frame within a primary screen coordinate system, wherein the position information of the microscopic highlight frame includes starting coordinates (OSDx, OSDy) and dimensions (OSDw, OSDh) of the microscopic highlight frame;
• a state scanning and updating unit configured to scan a movement state of the microscopic highlight frame within the primary screen coordinate system to obtain starting coordinates (OSDx′, OSDy′) of the microscopic highlight frame after movement;
• a position information reverse mapping unit configured to perform reverse mapping on the starting coordinates (OSDx′, OSDy′) of the microscopic highlight frame after movement to obtain starting coordinates (Zoomx′, Zoomy′) of the microscopic region virtual frame after movement;
• a content extraction unit configured to extract an image content within the microscopic region virtual frame based on the dimensions (Zoomw, Zoomh) and the starting coordinates (Zoomx′, Zoomy′) of the microscopic region virtual frame after movement;
• a display control unit configured to microscopically magnify an extracted image content within the microscopic region virtual frame on a secondary screen;
• wherein an aspect ratio of the primary screen is 16:9 and a resolution of the primary screen is Dw×Dn;
• the display image is magnified using a two-stage magnification strategy based on a change in the zoomLevel selected by the user;
• when the zoomLevel ranges from 0 to zoomLevel16R9, the display image is magnified using a first magnification strategy to adapt to a size of the primary screen, wherein the zoomLevel16R9 is a magnification level at which the display image first adapts to the size of the primary screen;
• when the zoomLevel ranges from zoomLevel16R9 to zoomLevelmax;
• the display image adapted to the size of the primary screen is proportionally magnified using a second magnification strategy, wherein the zoomLevelmax is a maximum magnification level;
• the first magnification strategy includes:
• when a condition Wo×Dh≥Ho×Dw is satisfied, the position information of the microscopic region virtual frame is expressed as:
• Zoom
• w
• =
• W
• o
• -
• 2
• ×
• 32
• ×
• ZoomLevel
• ;
• Zoom
• h
• =
• H
• o
• ;
• Zoom
• x
• =
• Zoom
• x
• ⁢
• 0
• -
• 32
• ;
• Zoom
• y
• =
• Zoom
• y
• ⁢
• 0
• ;
• when a condition Wo×Dh<H0×Dw is satisfied, the position information of the microscopic region virtual frame is expressed as:
• Zoom
• w
• =
• W
• o
• ;
• Zoom
• h
• =
• H
• o
• -
• 2
• ×
• 32
• ×
• ZoomLevel
• ;
• Zoom
• x
• =
• Zoom
• x
• ⁢
• 0
• ;
• Zoom
• y
• =
• Zoom
• y
• ⁢
• 0
• -
• 32
• ;
• the second magnification strategy includes:
• the position information of the microscopic region virtual frame is calculated upon a step of zoomLevel+1 for each microscopic control magnification level as follows:
• Zoom
• w
• =
• Zoom
• w
• ⁢
• 0
• -
• 32
• ×
• 2
• ;
• Zoom
• h
• =
• Zoom
• h
• ⁢
• 0
• -
• 32
• ×
• 2
• ;
• Zoom
• x
• =
• Zoom
• x
• ⁢
• 0
• -
• 32
• ;
• Zoom
• y
• =
• Zoom
• y
• ⁢
• 0
• -
• 32
• ;
• where (Zoomx0, Zoomy0) and (Zoomw0, Zoomh0) are the starting coordinates and the dimensions of the microscopic region virtual frame before the change in the magnification level, (Zoomx, Zoomy) and (Zoomw, Zoomh) are the starting coordinates and the dimensions of the microscopic region virtual frame determined based on the zoomLevel;
• wherein Wis a width of the display image, and H is a height of the display image.