YCbCrToRGB
Converts a YCbCr image to the RGB color model.
This function converts a Y'Cb'Cr' image src to a 24-bit gamma-corrected R'G'B' image dst according to the following formulas:
R' = 1.164*(Y' - 16) + 1.596*(Cr' - 128)
G' = 1.164*(Y' - 16) - 0.813*(Cr' - 128) - 0.392*(Cb' - 128)
B' = 1.164*(Y' - 16) + 2.017*(Cb' - 128)
The output R'G'B' values are saturated to the range [0, 255].
The fourth channel is created by setting channel values to the constant value aval.
The function interface declaration is as follows:
- Operation on pixel-order data:
HmppResult HMPPI_YCbCrToRGB_8u_C3R(const uint8_t* src, int32_t srcStep, uint8_t *dst, int32_t dstStep, HmppiSize roiSize);
HmppResult HMPPI_YCbCrToRGB_8u_AC4R(const uint8_t* src, int32_t srcStep, uint8_t *dst, int32_t dstStep, HmppiSize roiSize);
- Operation on planar data:
HmppResult HMPPI_YCbCrToRGB_8u_P3R(const uint8_t* src[3], int32_t srcStep, uint8_t *dst[3], int32_t dstStep, HmppiSize roiSize);
HmppResult HMPPI_YCbCrToRGB_8u_P3C3R(const uint8_t* src[3], int32_t srcStep, uint8_t *dst, int32_t dstStep, HmppiSize roiSize);
- Conversion from planar data to pixel-order data:
HmppResult HMPPI_YCbCrToRGB_8u_P3C4R(const uint8_t* src[3], int32_t srcStep, uint8_t *dst, int32_t dstStep, HmppiSize roiSize, uint8_t aval);
Parameters
Parameter |
Description |
Value Range |
Input/Output |
|---|---|---|---|
src |
Pointer to the source image. An array of pointers to the color planes of the source planar image. |
The value cannot be NULL. |
Input |
srcStep |
Distance between starts of consecutive lines in the source image, in bytes |
The value must be zero or a positive integer. |
Input |
dst |
Pointer to the destination image ROI. An array of pointers to the color planes of the destination planar image. |
The value cannot be NULL. |
Output |
dstStep |
Distance between starts of consecutive lines in the destination image, in bytes |
The value must be zero or a positive integer. |
Input |
roiSize |
Size of the ROI of the source and destination images, in pixels |
roiSize.width ∈ (0, INT_MAX], roiSize.height ∈ (0, INT_MAX] |
Input |
aval |
Constant value to create the fourth channel |
The value must be zero or a positive integer. |
Input |
Return Value
- Success: HMPP_STS_NO_ERR
- Failure: An error code is returned.
Error Codes
Error Code |
Description |
|---|---|
HMPP_STS_NULL_PTR_ERR |
The value of src is NULL. |
HMPP_STS_SIZE_ERR |
The value of roiSize is 0 or negative. |
HMPP_STS_STEP_ERR |
The value of srcStep is zero or negative. |
HMPP_STS_ROI_ERR |
roiSize.width x Number of channels x Number of bytes occupied by the data type > Step |
Example
#define SRC_BUFFER_SIZE_T 90
#define DST_BUFFER_SIZE_T 90
void TestExample_YCbCrToRGB()
{
HmppiSize roi = { 4, 4 };
const uint8_t src[SRC_BUFFER_SIZE_T] = {
11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33,
11, 22, 33, 44, 55, 66, 77, 88, 22, 88, 77, 66, 55, 44, 33
};
int32_t srcStep = 20 * sizeof(uint8_t);
int32_t dstStep = 15 * sizeof(uint8_t);;
uint8_t dst[DST_BUFFER_SIZE_T] = {0};
HmppResult result = HMPPI_YCbCrToRGB_8u_C3R(src, srcStep, dst, dstStep, roi);
printf("result = %d \ndst = ", result);
if (result != HMPP_STS_NO_ERR) {
printf("result error: %d\n", result);
}
int32_t dstWidth = dstStep / sizeof(uint8_t);
for(int32_t i = 0; i < DST_BUFFER_SIZE_T; i++){
if (i % dstWidth == 0) {
printf("\n");
}
printf("%3d ",dst[i]);
}
printf("\n");
}
int main()
{
TestExample_YCbCrToRGB();
}
Output:
result = 0 dst = 0 113 0 0 112 0 0 173 0 0 154 0 0 0 0 0 111 0 0 64 0 0 155 0 0 152 0 0 0 0 0 155 0 0 165 0 0 113 0 0 111 0 0 0 0 0 113 0 0 112 0 0 173 0 0 154 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0