Digital image interpolator using a plurality of interpolation kernals
First Claim
1. Digital image processing apparatus for performing two dimensional interpolation on a digital image expressed as rows and columns of pixel values, comprising:
- (a) an interpolation coefficient memory containing a plurality of one dimensional interpolation kernels for performing a plurality of interpolation types including cubic convolution, linear, and replication interpolation;
(b) row interpolator means connected to said memory for receiving successive image pixel values along a row, retrieving interpolation coefficients from said memory, and producing interpolated pixel values by multiplying and summing the pixel values and interpolation coefficients;
(c) column interpolator means connected to said row interpolator means and said memory for receiving rows of interpolated and noninterpolated pixel values from said row interpolator means, retrieving interpolation coefficients from said memory, and producing rows of interpolated pixel values by interpolating between groups of interpolated and noninterpolated pixel values in a column direction;
(d) logic and control means for selecting one of said kernels in response to an operator input; and
wherein said row interpolator means includes means for replicating the first and last pixel value in a row in an image, and said column interpolator means includes means for replicating the first and last rows of interpolated and noninterpolated pixel values in an image.
0 Assignments
0 Petitions
Accused Products
Abstract
An interpolator for enlarging or reducing a digital image includes an interpolation coefficient memory containing interpolation coefficients representing a one dimension interpolation kernel. A row interpolator receives image pixel values, retrieves interpolation coefficients from the memory, and produces interpolated pixel values by interpolating in a row direction. A column interpolator receives multiple rows of interpolated pixel values from the row interpolator, retrieves interpolation coefficients from the memory, and produces rows of interpolated pixel values by interpolating in a column direction.
81 Citations
10 Claims
-
1. Digital image processing apparatus for performing two dimensional interpolation on a digital image expressed as rows and columns of pixel values, comprising:
-
(a) an interpolation coefficient memory containing a plurality of one dimensional interpolation kernels for performing a plurality of interpolation types including cubic convolution, linear, and replication interpolation; (b) row interpolator means connected to said memory for receiving successive image pixel values along a row, retrieving interpolation coefficients from said memory, and producing interpolated pixel values by multiplying and summing the pixel values and interpolation coefficients; (c) column interpolator means connected to said row interpolator means and said memory for receiving rows of interpolated and noninterpolated pixel values from said row interpolator means, retrieving interpolation coefficients from said memory, and producing rows of interpolated pixel values by interpolating between groups of interpolated and noninterpolated pixel values in a column direction; (d) logic and control means for selecting one of said kernels in response to an operator input; and wherein said row interpolator means includes means for replicating the first and last pixel value in a row in an image, and said column interpolator means includes means for replicating the first and last rows of interpolated and noninterpolated pixel values in an image. - View Dependent Claims (5, 6, 7, 8, 9, 10)
-
-
2. A method of processing a digital image comprising the steps of:
-
selecting a format of an output digital image comprising at least first and second image bands, each of said bands having at least one digital image; determining first and second different interpolation parameters for said respective first and second image bands; processing a first digital image to be incorporated in said first image band of an output digital image with said first interpolation parameters; processing a second digital image to be incorporated in said second image band of said output digital image with said second interpolation parameters; and wherein said steps of processing said first and second digital images are effected by means of two-dimensional interpolation including; storing a plurality of one dimensional interpolation kernels for performing a plurality of interpolation types including cubic convolution, linear, and replication interpolation in an interpolation coefficient memory; performing row interpolation by receiving successive image pixel values along a row, retrieving interpolation coefficients from said memory, and producing interpolated pixel values by multiplying and summing the pixel values and interpolation coefficients; performing column interpolation by retrieving interpolation coefficients from said memory, and producing rows of interpolated pixel values by interpolating between groups of interpolated and noninterpolated pixel values in a column direction; and controlling the selection of one of said kernels in response to an operator input. - View Dependent Claims (3, 4)
-
Specification