Method and apparatus for zooming images on a video display
First Claim
1. An apparatus for enlarging a source image for display on a display device, the apparatus comprising:
- a scanline buffer for storing pixel values of a first row of the source image;
coordination circuitry for receiving and storing pixel values of a second row of the source image;
blend circuitry coupled to the scanline buffer and the coordination circuitry, the blend circuitry for generating output pixel values, each of the output pixel values corresponding to a weighted average of a plurality of input pixel values, the plurality of input pixel values comprising a plurality of pixel values stored in the scanline buffer and a plurality of pixel values stored in the coordination circuitry; and
control circuitry coupled to the scanline buffer, the coordination circuitry, and the blend circuitry, the control circuitry for determining weight values for computing the weighted average.
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Accused Products
Abstract
An apparatus and method for enlarging a source image on a computer display is described. A scanline buffer stores pixels in a first row of the source image. Coordination circuitry receives from a processor and stores pixels in a second row of the source image. Blend circuitry generates output pixels, such that each of the output pixels corresponds to a weighted average of a plurality of input pixels. The plurality of input pixels comprises two pixels stored in the scanline buffer and two pixels stored in the coordination circuitry. Control circuitry determines weight values and provides the weight values to the blend circuitry for calculating the weighted average. The control circuitry also determines, based on the weight values, which pixels stored in the scanline buffer and in the coordination circuitry are used by the blend circuitry as the input pixels. In addition, the control circuitry replaces the pixels in the scanline buffer with corresponding pixels from the coordination circuitry after the last time the pixels in the scanline buffer are used as the input pixels.
23 Citations
31 Claims
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1. An apparatus for enlarging a source image for display on a display device, the apparatus comprising:
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a scanline buffer for storing pixel values of a first row of the source image; coordination circuitry for receiving and storing pixel values of a second row of the source image; blend circuitry coupled to the scanline buffer and the coordination circuitry, the blend circuitry for generating output pixel values, each of the output pixel values corresponding to a weighted average of a plurality of input pixel values, the plurality of input pixel values comprising a plurality of pixel values stored in the scanline buffer and a plurality of pixel values stored in the coordination circuitry; and control circuitry coupled to the scanline buffer, the coordination circuitry, and the blend circuitry, the control circuitry for determining weight values for computing the weighted average. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for enlarging a source image on a computer display, comprising:
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a scanline buffer for storing a scanline, the scanline comprising pixel values for each pixel in a first row of the source image, the source image having a plurality of rows of pixels, each of the rows having P pixels, where P is an integer; a memory device coupled to a processor for receiving from the processor pixel values of pixels in a second row of the source image; a data word register coupled to the memory device for receiving from the memory device and storing data words, each data word corresponding to at least one of the pixels of the second row of the source image; a C-D register coupled to the data word register for receiving and storing pixel values of the Nth pixel and the (N+1)th pixel of the second row of the source image, where N is an integer; blending circuitry coupled to the C-D register and the scanline buffer for generating output pixel values of an output image, each of the output pixel values representing a weighted average of a plurality of input pixel values, the plurality of input pixel values comprising the Nth and (N+1)th pixel values of the scanline, and the Nth and (N+1)th pixel values of the second row of the source image stored in the coordination circuitry, and control circuitry coupled to the scanline buffer, the blending circuitry, the C-D register, and the data word register, the control circuitry storing values Xfrac and Yfrac to be used by the blending circuitry in computing the weighted average, the control circuitry incrementing Xfrac by a predetermined value Xfrac-- incr each time the blending circuitry generates an output pixel value, such that N is incremented by one each time Xfrac exceeds a first predetermined value and N is reset to one if N exceeds P, the control circuitry resetting Xfrac to a second predetermined value if Xfrac exceeds the first predetermined value, the control circuitry causing the pixel value of the Nth pixel of the scanline to be replaced with the pixel value of the Nth pixel of the second row of the source image stored in the coordination circuit after the blending circuitry generates the last output intensity level for which the Nth pixel value of the scanline is used as one of the input pixel values, the control circuitry incrementing Yfrac by a predetermined value Yfrac-- incr once each time the blending circuitry generates a complete row of output pixel values, such that the second row of the source image is replaced by the next vertically adjacent row of the source image each time Yfrac exceeds a fourth predetermined value, the control circuitry resetting Yfrac to a third predetermined value if Yfrac exceeds the fourth predetermined values. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method of enlarging a source image on a video display, comprising the steps of:
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a) storing in a storage buffer pixel values of a single row of the source image received from a processor; b) determining weight values corresponding to factors by which the source image is to be enlarged; c) providing to a blend circuit a plurality of sets of input pixel values, each of the sets of input pixel values comprising two pixel values stored in the storage buffer and two pixel values from a second row of the source image received from the processor; d) determining based on the weight values which of the pixel values in the storage buffer and in the second row of the source image are to be included in each of the sets of input pixel values; e) using the blend circuit to generate a plurality of output pixel values, each of the output pixel values corresponding to a weighted average of one of the sets of input pixel values; and f) replacing predetermined pixel values in the storage buffer with corresponding pixel values from the second row of the source image, each of the predetermined pixel values being replaced after the blend circuit has generated the last output pixel value for which the predetermined pixel value was used as an input pixel value wherein the predetermined pixel values are determined based on the weight values; g) repeating steps b) through f) such that the pixel value of each pixel of the source image is used by the blend circuit in at least one of the sets input pixel values for generating at least one of the output pixel values. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. An apparatus for enlarging a source image, comprising:
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a buffer for storing pixel values of a single row of the source image; a first circuit for receiving from a processor and storing pixel values of a second row of the source image; a second circuit coupled to the buffer and the first circuit, the second circuit for generating output pixel values, each of the output pixel values corresponding to a weighted average of a plurality of input pixel values; and a third circuit coupled to the buffer, the first circuit, and the second circuit, the third circuit for determining the weighted average.
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27. In a computer system including a processor and a display device, a method of enlarging a source image for display by the display device, the method comprising the steps of:
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a) receiving pixel values of a single row of the source image from the processor; b) storing the pixel values of the single row of the source image in a storage buffer; c) receiving pixel values of a second row of the source image from the processor; d) determining weight values corresponding to factors by which the source image is to be enlarged; e) determining, based on the weight values, which of the pixel values in the storage buffer and in the second row of the source image are to be used as input pixel values for generating each of a plurality of output pixel values; and f) generating the plurality of output pixel values, each of the output pixel values corresponding to a weighted average of a set of the input pixel values. - View Dependent Claims (28, 29)
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30. An apparatus for enlarging a source image for display on a display device, the apparatus comprising:
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buffer means for storing pixel values of only a first row of the source image; coordination means for receiving from a processor and storing pixel values of a second row of the source image; blend means for generating a plurality of output pixel values, each of the output pixel values representing a weighted average of a plurality of input pixel values, the plurality of input pixel values comprising a plurality of the pixel values stored in the buffer means and a plurality of the pixel values stored in the coordination means; and control means for providing weight values to the blend means corresponding to the weighted average and for determining which pixels stored in the buffer means and in the coordination means are used by the blend means as the input pixel values. - View Dependent Claims (31)
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Specification