Hardware rotation of an image on a computer display
AssigneeSeiko Epson Corporation
InventorYung Ling Chan
Life of this patent
Estimating the term…
Abstract
An address generator (FIG. 6) of a display controller (16) includes an adder (62) that repetitively adds an image-row-offset value to the address generator's address output so that data sequentially fetched from a refresh memory (18) to refresh a display (20) properly represent the image data even though the display scanning orthogonal to the image data's sequence in the refresh memory. As the data are fetched, an omega network (90) re-orders the bits within the fetched data words in accordance with the current display scan so that the display will receive proper data even though each location contains data for a plurality of pixels in an orthogonally oriented image row.
Claims9
A device for rotating an image for display, comprising:
- a central-processing unit for generating update data signals representing the values of picture elements arrayed in image-pixel rows and columns and for generating corresponding update-address signals for an image memory in a first orientation, the first orientation being one of portrait or landscape, the update-address signals identifying rows and columns of the picture elements whose values the update data signals represent;
- and
- a refresh-address generator that translates the update-address signals into translated refresh-address signals and applies the translated refresh-address signals to an image memory in a second orientation, the second orientation being the other of portrait or landscape, the translated refresh-address signals sequentially identifying successive memory-row positions along each of a plurality of successively scanned memory columns.
A device for rotating an image for display on a display device, the device for rotating for communication with a central-processing unit that generates update data signals representing the values of picture elements arrayed in image-pixel rows and columns and that generates corresponding update-address signals for an image memory in a first orientation, the first orientation being one of portrait or landscape, the update-address signals identifying rows and columns of the picture elements whose values the update data signals represent, the device for rotating comprising:
- a refresh-address generator that translates the update-address signals into translated refresh-address signals and applies the translated refresh-address signals to an image memory in a second orientation, the second orientation being the other of portrait or landscape, the translated refresh-address signals sequentially identifying successive memory-row positions along each of a plurality of successively scanned memory cloumns.
Dependencies are inferred from the claim text.