# Is there are example usage code of this NPP Function nppiLUT_Trilinear_8u_AC4IR

Hi All,

Here is the function I’m thinking of using. Any source code usage example available?
Should I been concerned when I check the internet and there are no examples of this function being used, i.e. not used because?

I have 1 question concerning this function:

  1. What is pValues pointing too.  Please provide source code example.

Thanks.

Tom


public static int nppiLUT_Trilinear_8u_AC4IR(TypedPointer pSrcDst,
int nSrcDstStep,
NppiSize oSizeROI,
TypedPointer pValues,
TypedPointer pLevels,
int aLevels)
Four channel 8-bit unsigned 3D trilinear interpolated look-up-table in place color conversion, not affecting alpha.
Alpha channel is the last channel and is not processed.

The LUT is derived from a set of user defined mapping points through trilinear interpolation.
Parameters:
pSrcDst - \ref in_place_image_pointer.
nSrcDstStep - \ref in_place_image_line_step.
oSizeROI - \ref roi_specification.
pValues - Device pointer aLevels[2] number of contiguous 2D x,y planes of 4-byte packed RGBX values containing the user defined base OUTPUT values at that x,y, and z (R,G,B) level location. Each level must contain x * y 4-byte packed pixel values (4th byte is used for alignement only and is ignored) in row (x) order.
pLevels - Host pointer to an array of 3 host pointers, one per cube edge, pointing to user defined INPUT level values.
aLevels - Host pointer to an array of 3 user defined number of input/output mapping points, one per 3D cube edge. aLevels[0] represents the number of x axis levels (Red), aLevels[1] represents the number of y axis levels (Green), and aLevels[2] represets the number of z axis levels (Blue).
Returns:
\ref image_data_error_codes, \ref roi_error_codes - ::NPP_LUT_NUMBER_OF_LEVELS_ERROR if the number of levels is less than 2 or greater than 256.

Hi,

We don’t have a tri-linear sample but here is a sample for linear case for your reference:
/usr/local/cuda-10.0/samples/7_CUDALibraries/histEqualizationNPP/

Thanks.