I420 to RGB/RGBA Color Conversion¶
Converts an image from I420 format to RGB or RGBA format.
Description
This function can operate with ROI (see Image Regions of Interest).
This function performs conversion from I420 image to gamma-corrected RGB or RGBA image according to formulae:
R' = 1.164 * (Y' - 16) + 1.596 * (Cr' - 128)G' = 1.164 * (Y' - 16) - 0.183 * (Cr' - 128) - 0.392 * (Cb' - 128)B' = 1.164 * (Y' - 16) + 2.017 * (Cb' - 128)
Source and destination image width and height should be even.
If destination format is RGBA, alpha_value from spec shall be used to fill alpha channel.
Source and destination image width and height should be even.
Headers
oneapi/ipl/convert.hpp
Syntax
-
template<typename ComputeT = float, typename SrcDataT, typename SrcAllocatorT, formats DstFormat, typename DstDataT, typename DstAllocatorT>
sycl::event oneapi::ipl::convert(sycl::queue &queue, image<formats::i420, SrcDataT, SrcAllocatorT> &src, image<DstFormat, DstDataT, DstAllocatorT> &dst, const convert_spec<DstDataT> &spec = {}, const std::vector<sycl::event> &dependencies = {})¶ Function for I420 to RGB or RGBA color conversion.
- Template Parameters
ComputeT – The type in which all calculations will be performed
SrcDataT – Source image data type
SrcAllocatorT – Source image allocator type
DstFormat – Destination image color format
DstDataT – Destination image data type
DstAllocatorT – Destination image allocator type
- Parameters
queue – SYCL queue object
src – Source image object
dst – Destination image object
spec – Specification for convert function
dependencies – SYCL event dependencies
- Returns
SYCL event
Supported values for ComputeT:
|
|
Supported values for DstFormat:
|
|
Parameters
See Parameters of Color Conversion (spec).
Errors
compile-time format check |
Indicates an error when image format is not supported. |
compile-time data type check |
Indicates an error when image data type is not supported. |
compile-time compute data type check |
Indicates an error when compute data type is not supported. |
|
Indicates an error when ROI sizes of the source image and the destination image are not equal. |
|
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 to use the
oneapi::ipl::convert for I420 to RGBA conversion:
#include <vector>
// std::vector with data for source image
std::vector<std::uint8_t> src_image_data{
236, 236, 236, 236,
236, 236, 236, 236,
236, 236, 236, 236,
236, 236, 236, 236,
128, 128, 128, 128,
128, 128, 128, 128
};
// Create queue
sycl::queue queue{};
shared_usm_allocator_t usm_allocator{ queue };
// Source i420 image data (usm_image)
image<formats::i420, std::uint8_t> src_image{ queue, src_image_data.data(), src_size, usm_allocator };
// Destination rgba image data (image_image)
image<formats::rgba, std::uint8_t> dst_image{ src_size };
(void)convert(queue, src_image, dst_image);