A nonlinear processing device comprising: nonlinear processing means (17R, 17G, 17B) operable to correct a signal level of a video signal (DRB, DGB, DBB) using nonlinear processing according to the voltage-light transmittance characteristics of an image display unit (52R, 52G, 52B) to output the corrected signal as a first corrected video signal (DRC, DGC, DBC); horizontal and vertical position determining means (55R, 55G, 55B) operable to determine a position in a horizontal direction and a vertical direction of a pixel in said video signal (DRB, DGB, DBB); level block determining means operable to determine a signal level block of the pixel in said video signal (DRB, DGB, DBB), the signal level block being a signal level range to which the signal level of the pixel belongs; level boundary setting means operable to variably set a group of level boundary values {1, 2,...,r) which define the maximum and minimum signal levels of a plurality of signal level blocks to be used in the determination by said level block determining means; first correction means operable to generate a video signal correction signal (DRS, DGS, DBS) according to the position in the horizontal direction and the vertical direction determined by said horizontal and vertical position determining means (55R, 55G, 55B) the signal level block determined by said level block determining means, and to output the video signal correction signal (DRS, DGS, DBS); and combining means (19R, 19G, 19B) operable to combine the first corrected video signal (DRC, DGC, DBC) output by said nonlinear processing means (17R, 17G, 17B) with the video signal correction signal (DRS, DGS, DBS) output by said first correction means (18R, 18G, 18B) and to output a third corrected video signal (DRD, DGD, DBD), characterized in that: said level boundary setting means comprises a level arrangement data memory having memory areas storing various groups of level boundary values, and a level arrangement data selector adapted to select one of the groups of level boundary values from the stored groups of level boundary values on the basis of a selection control signal (DSEL) and to supply the group of level boundary values to said level block determining means; and the level block determining means is operable to use the selected group of level boundary values for determination of said signal level block. nonlinear processing means (17R, 17G, 17B) operable to correct a signal level of a video signal (DRB, DGB, DBB) using nonlinear processing according to the voltage-light transmittance characteristics of an image display unit (52R, 52G, 52B) to output the corrected signal as a first corrected video signal (DRC, DGC, DBC); horizontal and vertical position determining means (55R, 55G, 55B) operable to determine a position in a horizontal direction and a vertical direction of a pixel in said video signal (DRB, DGB, DBB); level block determining means operable to determine a signal level block of the pixel in said video signal (DRB, DGB, DBB), the signal level block being a signal level range to which the signal level of the pixel belongs; level boundary setting means operable to variably set a group of level boundary values {1, 2,...,r) which define the maximum and minimum signal levels of a plurality of signal level blocks to be used in the determination by said level block determining means; first correction means operable to generate a video signal correction signal (DRS, DGS, DBS) according to the position in the horizontal direction and the vertical direction determined by said horizontal and vertical position determining means (55R, 55G, 55B) the signal level block determined by said level block determining means, and to output the video signal correction signal (DRS, DGS, DBS); and combining means (19R, 19G, 19B) operable to combine the first corrected video signal (DRC, DGC, DBC) output by said nonlinear processing means (17R, 17G, 17B) with the video signal correction signal (DRS, DGS, DBS) output by said first correction means (18R, 18G, 18B) and to output a third corrected video signal (DRD, DGD, DBD), said level boundary setting means comprises a level arrangement data memory having memory areas storing various groups of level boundary values, and a level arrangement data selector adapted to select one of the groups of level boundary values from the stored groups of level boundary values on the basis of a selection control signal (DSEL) and to supply the group of level boundary values to said level block determining means; and a level arrangement data memory having memory areas storing various groups of level boundary values, and a level arrangement data selector adapted to select one of the groups of level boundary values from the stored groups of level boundary values on the basis of a selection control signal (DSEL) and to supply the group of level boundary values to said level block determining means; and the level block determining means is operable to use the selected group of level boundary values for determination of said signal level block.