Image correction method
View Patent ↗Disclosed is an image correction method of correcting an image including a number of horizontal image scan lines each corresponding to a number of pieces of image data. The method includes the following steps: segmenting each of the horizontal image scan lines into a plurality of segments according to a plurality of nodes, each of the segments having an original segment length; looking up a table to generate at least one correction parameter according to a selection signal; generating a gain value according to a control signal; correcting the original segment length to generate an adjusted segment length according to the gain value and the correction parameter; and altering positions of the plurality of nodes to correct the image according to the adjusted segment length.
1. An image correction method for a cathode ray tube (CRT) television system, the method comprising the steps of:
(a) responding to an operation event to obtain a plurality of gain values;
(b) determining n offsets, which respectively correspond to n segments between any two adjacent nodes of (n+1) nodes, according to the gain values and a plurality of correction functions corresponding to the gain values, each of the n segments having an original segment length, wherein n is a natural number;
(c) correcting the original segment lengths of the n segments to generate n adjusted segment lengths according to the n offsets;
(d) determining corrected positions of the (n+1) nodes according to the n adjusted segment lengths and a data enable signal; and
(e) determining pixel positions and corresponding image data between the two adjacent nodes of the (n+1) nodes according to ratios of the n adjusted segment lengths to the corresponding n original segment lengths.
2. The method according to claim 1 , wherein the step (d) comprises:
(d1) accumulating the n adjusted segment lengths to obtain a horizontal scan line length;
(d2) searching back by one half of the horizontal scan line length from a middle time point of an enable period of the data enable signal to obtain the corrected position of a starting node of the (n+1) nodes; and
(d3) determining the corrected positions of the other n nodes according to the starting node and the adjusted segment lengths.
3. The method according to claim 1 , wherein the step (e) performs an interpolation operation according to the ratios of the n adjusted segment lengths to the corresponding n original segment lengths, and a plurality of pieces of pixel data of the n original segment lengths to obtain the pixel data of the n adjusted segment lengths.
4. The method according to claim 1 , wherein the correction functions comprise an outer frame correction function, an inner frame correction function and a local correction function.
5. The method according to claim 4 , wherein the correction functions are sine wave functions.
6. The method according to claim 4 , wherein the correction functions are polynomial functions.
7. The method according to claim 1 , wherein the step
(b) further comprises:
generating a correction parameter in correspondence with each of the segments, wherein each of the segments corresponds to the same correction parameter.
8. The method according to claim 1 , wherein the step
(b) further comprises:
generating a correction parameter in correspondence with each of the segments, wherein each of the segments corresponds to different correction parameters.
9. The method according to claim 8 , wherein the step (d) further comprises:
multiplying the correction parameters by the gain values to generate the n offsets corresponding to the segment lengths; and
adding each of the original segment lengths to the corresponding n offsets to generate the n adjusted segment lengths,
wherein the sum of all of the n offsets is equal to zero.
10. The method according to claim 1 , further comprising the step of:
setting a horizontal image zone, which comprises a plurality of horizontal image scan lines;
wherein the horizontal image zone and any two adjacent segments constitute a local correction zone corresponding to a correction function.
11. The method according to claim 1 , further comprising the steps of:
setting a first horizontal image zone, which comprises a plurality of first horizontal image scan lines;
setting a second horizontal image zone, which comprises a plurality of second horizontal image scan lines,
wherein the first horizontal image zone abuts upon the second horizontal image zone, and the first horizontal image zone, the second horizontal image zone and any two adjacent segments constitute a local correction zone, which corresponds to a correction function.
12. The method according to claim 1 , wherein the image is an image of a cathode ray tube (CRT) television system.
13. The method according to claim 1 , wherein the image data are digital image data.