hi_isp_awb_in_out_attr
Description
Defines the parameters for determining the outdoor or indoor scenario.
Definition
typedef struct {
hi_bool enable;
hi_op_mode op_type;
hi_isp_awb_indoor_outdoor_status outdoor_status;
hi_u32 out_thresh;
hi_u16 low_start;
hi_u16 low_stop;
hi_u16 high_start;
hi_u16 high_stop;
hi_bool green_enhance_en;
hi_u8 out_shift_limit;
} hi_isp_awb_in_out_attr;
Members
|
Member |
Description |
|---|---|
|
enable |
Outdoor/Indoor scenario determination enable The options are as follows:
|
|
op_type |
Operation type for determining the outdoor/indoor scenario (automatic or manual). The options are as follows:
|
|
outdoor_status |
Indoor or outdoor status information input by you in manual mode. The options are as follows:
|
|
out_thresh |
Threshold for determining the outdoor/indoor scenario (exposure time in the unit of µs). A value less than the threshold indicates the outdoor scenario. |
|
low_start |
Start value of the low temperature zone for decreasing the weight of the pixels in the low color temperature range. The recommended value is 5000K. |
|
low_stop |
End value of the low temperature zone for decreasing the weight of the pixels in the low color temperature range. The recommended value is 4500K. Value range: (0, low_start) |
|
high_start |
Start value of the high temperature zone for decreasing the weight of the pixels in the high color temperature range. The recommended value is 6500K. Value range: (low_start, 0xFFFF] |
|
high_stop |
End value of the high temperature zone for decreasing the weight of the pixels in the high color temperature range. The recommended value is 8000K. Value range: (high_start, 0xFFFF] |
|
green_enhance_en |
Green channel enhancement enable in the green plant scenario. The options are as follows:
|
|
out_shift_limit |
White point range limit for the AWB algorithm in the outdoor scenario (shift = out_shift_limit). Value range: [0x0, 0xFF]. |
Restrictions
- out_thresh needs to be adjusted based on the photosensitive characteristics of the sensor. Equivalent exposure time = Exposure time x Analog gain x Digital gain x ISP digital gain.
- When you use your own AE algorithm library and the indoor or outdoor scenario is determined automatically, ensure that the current exposure time and ISO are transferred to the AWB algorithm library.
- low_start, low_stop, high_start, and high_stop are used to set the color temperature range, and they are related to sensor correction. You are advised to fine-tune the sensor. The value range of the four parameters is low_stop < low_start < high_start < high_stop. If the outdoor color temperature range [low_start, high_start] is wide, the color effect may not be good in the outdoor scenario with a large single-color area. If the range [low_start, high_start] is narrow, the AWB cannot be completely restored in the high or low color temperature scenarios such as the sunset scenario. As a result, the image has a yellow cast at a low color temperature and has a blue cast at a high color temperature.
- After AWB correction parameters are adjusted, low_start, low_stop, high_start, and high_stop need to be adjusted again to achieve the optimal effect.
- shift affects the performance of the AWB algorithm. The values of shift_limit and out_shift_limit have little impact on the AWB result in command scenarios, but have great impact on the AWB result in the special illuminant and large-area single-color scenarios.
- When the values are small, the single-color effect is good, but the color cast easily occurs under special illuminants.
- When the values are large, the AWB performance is stable, but the color cast may occur in large green and yellow areas.
Figure. Parameters of outdoor color temperature range
