Browse Prior Art Database

Image Rotation

IP.com Disclosure Number: IPCOM000042828D
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Martinez, RT: AUTHOR

Abstract

A computer is programmed to rotate raster patterns to any one of four orthogonal positions about any one of a plurality of rotating points. During rotation, image reversal can be achieved. The raster pattern is first serialized into a single bit string. The programmed processor, in accordance with the desired rotation, transfers on a bit-by-bit basis the image-representing signals from the serialized bit string into a second serialized bit string having different positions representative of the desired rotation. The second bit string is then utilized for presenting the image in the newly rotated orientation. Referring to the drawing, the original image raster has five identifiable points A through E. As described, rotation of the image raster is about point A.

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Image Rotation

A computer is programmed to rotate raster patterns to any one of four orthogonal positions about any one of a plurality of rotating points. During rotation, image reversal can be achieved. The raster pattern is first serialized into a single bit string. The programmed processor, in accordance with the desired rotation, transfers on a bit-by-bit basis the image-representing signals from the serialized bit string into a second serialized bit string having different positions representative of the desired rotation. The second bit string is then utilized for presenting the image in the newly rotated orientation. Referring to the drawing, the original image raster has five identifiable points A through E. As described, rotation of the image raster is about point A. Programming is adaptable so that the image raster can be rotated about any of the four corner points A through D or about any arbitrary point within the raster itself as represented by point E. Firstly, the image raster is serialized into a single bit stream and stored in a first memory area. The type of image rotation is determined. Then the various segments of the image raster, as stored in the first memory area, are analyzed with the first byte to be manipulated being identified for a 180-degree rotation, as shown by the two arrows in the drawing. The first byte corresponds to the first byte adjacent point A. Then within that byte the bits to be transferred are identified (reversed in the instance of a 180-degree rotation), then transferred to the ending portion of a serial bit stream being constructed in the second memory area. Other bytes and bits ar...