MimWarpList

This function transforms a list of coordinates (points) using the specified warping matrix and stores the resulting coordinates in the destination arrays (M_REVERSE). Alternatively, this function can transform the coordinates using the inverse of the specified matrix (M_FORWARD).

When this function transforms the coordinates using the warping matrix as is (M_REVERSE), it is referred to as a reverse warping transformation because this is how MimWarp() associates each pixel position of its destination buffer, (x_d, y_d ), with a specific point in its source buffer, (x_s, y_s ). Therefore, you can use MimWarpList() to establish which points in a source image MimWarp() associates with destination pixels when using the same matrix. When this function transforms the coordinates using the inverse of the specified warping matrix (M_FORWARD), it is referred to as a forward warping transformation; you can use a forward warping transformation, for example, to see if a specific pixel in the source image of MimWarp() is actually mapped to a destination buffer pixel.

You can only specify the coefficients for a 3x3 or 3x2 matrix; this allows you to perform a first-order polynomial warping or a perspective polynomial warping.

Perform a first-order polynomial warping by passing a 3x3 matrix, where the third row has the coefficients [0,0,1], or by passing a 3x2 matrix, the last row is assumed to be [0,0,1]. Perform a perspective polynomial warping by passing a 3x3 matrix, where the third row does not have the coefficients [0,0,1]. The matrix is applied as follows:

x _d = (a₀ x _s + a₁ y _s + a₂)/(c₀ x _s + c₁ y _s + c₂).

y _d = (b₀ x _s + b₁ y _s + b₂)/(c₀ x _s + c₁ y _s + c₂).

If a 3x2 matrix, or a 3x3 matrix whose third row has the coefficients of [0,0,1] is specified (for a first-order polynomial warping operation), the denominator resolves to 1, effectively leaving only the numerator. The coefficients can be automatically generated using MgenWarpParameter(), MimResize(), MimRotate(), or MimTranslate(), or can be user-established.

Note that MimWarpList() will internally invert the coefficients matrix (a₀...a₂, b₀...b₂, c₀...c₂ ) for a forward transfomation (M_FORWARD).