# OpenSolaris 2009.06 - man page for mlib_imagepolynomialwarptable (opensolaris section 3mlib)

mlib_ImagePolynomialWarpTable(3MLIB) mediaLib Library Functions mlib_ImagePolynomialWarpTable(3MLIB)mlib_ImagePolynomialWarpTable - polynomial-based image warp with table-driven interpolationNAMEcc [ flag... ] file...SYNOPSIS[ library... ] #include <mlib.h> mlib_status mlib_ImagePolynomialWarpTable(mlib_image *dst, const mlib_image *src, const mlib_d64 *xCoeffs, const mlib_d64 *yCoeffs, mlib_s32 n, mlib_d64 preShiftX, mlib_d64 preShiftY, mlib_d64 postShiftX, mlib_d64 postShiftY, mlib_d64 preScaleX, mlib_d64 preScaleY, mlib_d64 postScaleX, mlib_d64 postScaleY, const void *interp_table, mlib_edge edge);-lmlibThe mlib_ImagePolynomialWarpTable() function performs a polynomial-based image warp with table-driven interpolation. The images must have the same type, and the same number of channels. The images can have 1, 2, 3, or 4 channels. The data type of the images can be MLIB_BYTE, MLIB_SHORT, MLIB_USHORT, or MLIB_INT. The source and destination images may have different sizes. The xCoeffs and yCoeffs parameters must contain the same number of coefficients of the form (n + 1)(n + 2)/2 for some n, where n is the degree power of the polynomial. The coefficients, in order, are associated with the terms: 1, x, y, x**2, x*y, y**2, ..., x**n, x**(n-1)*y, ..., x*y**(n-1), y**n and coefficients of value 0 cannot be omitted. The image pixels are assumed to be centered at .5 coordinate points. In other words, the upper-left corner pixel of an image is located at (0.5, 0.5). For each pixel in the destination image, its center point D is backward mapped to a point S in the source image. Then the source pixels with their centers surrounding point S are selected to do the interpolation specified by interp_table to generate the pixel value for point D. The mapping is defined by the two bivariate polynomial functions X(x, y) and Y(x, y) that map destination (x, y) coordinates to source X and Y positions respectively. The functions X(x, y) and Y(x, y) are: preX = (x + preShiftX)*preScaleX preY = (y + preShiftY)*preScaleY n i warpedX = SUM {SUM {xCoeffs_ij * preX**(i-j) * preY**j}} i=0 j=0 n i warpedY = SUM {SUM {yCoeffs_ij * preX**(i-j) * preY**j}} i=0 j=0 X(x, y) = warpedX*postScaleX - postShiftX Y(x, y) = warpedY*postScaleY - postShiftY The destination (x, y) coordinates are pre-shifted by (preShiftX, preShiftY) and pre-scaled by the factors preScaleX and preScaleY prior to the evaluation of the polynomial. The results of the polynomial evaluations are scaled by postScaleX and postScaleY, and then shifted by (-postShiftX, -postShiftY) to produce the source pixel coordinates. This process allows for better precision of the results and supports tiled images.DESCRIPTIONThe function takes the following arguments: dst Pointer to destination image. src Pointer to source image. xCoeffs Destination to source transform coefficients for the X coordinate. yCoeffs Destination to source transform coefficients for the Y coordinate. n Degree power of the polynomial. preShiftX Displacement to apply to destination X positions. preShiftY Displacement to apply to destination Y positions. postShiftX Displacement to apply to source X positions. postShiftY Displacement to apply to source Y positions. preScaleX Scale factor to apply to destination X positions. preScaleY Scale factor to apply to destination Y positions. postScaleX Scale factor to apply to source X positions. postScaleY Scale factor to apply to source Y positions. interp_table Pointer to an interpolation table. The table is created by the mlib_ImageInterpTableCreate() function. edge Type of edge condition. It can be one of the following: MLIB_EDGE_DST_NO_WRITE MLIB_EDGE_SRC_PADDEDPARAMETERSThe function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.RETURN VALUESSee attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Committed | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ATTRIBUTESmlib_ImageInterpTableCreate(3MLIB), mlib_ImageInterpTableDelete(3MLIB), mlib_ImagePolynomialWarpTable_Fp(3MLIB), mlib_ImagePolynomial- Warp(3MLIB), mlib_ImagePolynomialWarp_Fp(3MLIB), attributes(5)SEE ALSOSunOS 5.112 Mar 2007 mlib_ImagePolynomialWarpTable(3MLIB)