Grayscale to RGB/RGBA Color Conversion#

Converts an image from grayscale format to RGB or RGBA format.


This function can operate with ROI (see Image Regions of Interest).

This function performs conversion from grayscale to RGB or RGBA image by copying luminance component to color components. If destination layout is channel4 (format is RGBA) , alpha_value from spec shall be be used to fill alpha channel.


Headers: oneapi/ipl/convert.hpp


template<typename SrcImageT, typename DstImageT>
sycl::event oneapi::ipl::gray_to_rgb(sycl::queue &queue, SrcImageT &src, DstImageT &dst, const color_conversion_spec<typename DstImageT::data_t> &spec = {}, const std::vector<sycl::event> &dependencies = {})#

Function for grayscale to RGB or RGBA color conversion.

Template Parameters
  • SrcImageT – Source image type

  • DstImageT – Destination image type

  • queue – SYCL queue object

  • src – Source image object

  • dst – Destination image object

  • spec – Specification for convert function

  • dependencies – SYCL event dependencies


SYCL event

Supported values for destination layout:




See Parameters of Color Conversion (spec).


compile-time memory layout check

Indicates an error when image memory layout is not supported.

compile-time data type check

Indicates an error when image data type is not supported.

invalid_argument exception

Indicates an error when ROI sizes of the source image and the destination image are not equal.

invalid_argument exception

Indicates an error when one of the pitch values is not divisible by size of component data type in bytes.

The code example below demonstrates how shall be called oneapi::ipl::gray_to_rgb for grayscale to RGBA conversion:

using namespace oneapi;

sycl::queue                 queue;
ipl::shared_usm_allocator_t allocator{ queue };
const sycl::range<2>        image_size{ height, width };

// Source image for grayscale data
ipl::image<ipl::layouts::plane, std::uint8_t> src_image{ queue, p_image_data, image_size, allocator };
// Destination image for RGBA data
ipl::image<ipl::layouts::channel4, std::uint8_t> dst_image{ image_size, allocator };

// Convert gray to RGBA
auto event = ipl::gray_to_rgb(queue, src_image, dst_image);