colorspace problem in jpegNPP


I have some inquiries regarding colorspace in the library provided by Nvidia.
We are currently developing a program that converts HEIF image files into JPEG image files.
At this time, I am using NvEnc’s HEVC Decorder and JPEG Encoder library of jpegNPP.

The problem is that the color of the JPEG image generated through HEVC Decorder and JPEG Encoder is different from the color of the original HEIF image.
I have tried several colorspace conversions to make the same color as the generated JPEG image and the original image, but I have not got the expected result.

Below is a screenshot that you can check out to see the results of the colorspace conversion.
-> = 1NPQBIExHWABk6arF6_rzNA6BQ4rxn3Sg

The below is the jpegNPP functions used for JPEG encoding.

  • nppiDCQuantFwd8x8LS_JPEG_8u16s_C1R_NEW
  • nppiEncodeOptimizeHuffmanScan_JPEG_8u16s_P3R

We couldn’t get the desired result in the way that we can try it.
(For reference, the heif decoding results at show the same color as the original.)

Under the present circumstances,
Would I ask you to answer what I need to process to get the JPEG image file which have no color differences?

Thank you.