28. LCAC

28.1. Function Overview

Color distortion correction. Due to the different refractive index of different colors, purple fringing is easy to form around objects at the junction of high-brightness areas and low-brightness areas. This module realizes the image de-purple fringing function and improves the purple fringing phenomenon at the edge of the image.

28.2. API Reference

28.2.1. CVI_ISP_SetLCACAttr

【Description】

Set gamma attribute parameters

【Syntax】

CVI_S32 CVI_ISP_SetLCACAttr(VI_PIPE ViPipe, const ISP_LCAC_ATTR_S *pstLCACAttr);

【Parameter】

Parameter

Description

Input/Output

ViPipe

VI_PIPE number

Input

pstLCACAttr

Gamma property parameters

Input

【Return Value】

Return value

Description

0

Success

Non 0

Failure. An error code is returned. For details, see chapter Error Codes.

【Requirement】

  • Header files: cvi_isp.h, cvi_comm_isp.h

  • Library files: libisp.so

【Note】

None.

【Example】

None.

【Related topic】

28.2.2. CVI_ISP_GetLCACAttr

【Description】

Get gamma attribute parameters

【Syntax】

【Parameter】

Parameter

Description

Input/Output

ViPipe

VI_PIPE number

Input

pstLCACAttr

Gamma property parameters

Output

【Return Value】

Return value

Description

0

Success

Non 0

Failure. An error code is returned. For details, see chapter Error Codes.

【Requirement】

  • Header files: cvi_isp.h, cvi_comm_isp.h

  • Library files: libisp.so

【Note】

None.

【Example】

None.

【Related topic】

28.3. Data Types

28.3.1. ISP_LCAC_GAUSS_COEF_ATTR_S

【Description】

Gamma Gauss parameter

【Syntax】

 typedef struct _ISP_LCAC_GAUSS_COEF_ATTR_S {
  CVI_U8 Wgt;
  CVI_U8 Sigma;
} ISP_LCAC_GAUSS_COEF_ATTR_S;

【Member】

Member

Description

Wgt

Control the degree of purple fringing according to the edge strength, and determine the weight curve of the fusion of the purple fringing result and the original image. The larger the Wgt, the larger the ratio of the fusion original image

Value range: [0x0, 0x80]

Data type: CVI_U8

Sigma

Control the degree of purple fringing according to the edge strength, and determine the weight curve of the fusion of the purple fringing result and the original image. The larger the Sigma, the more pixels are fused with the original image

Value range: [0x0, 0xff]

Data type: CVI_U8

【Note】

None.

【Related Data Type and Interface】

None.

28.3.2. ISP_LCAC_MANUAL_ATTR_S

【Description】

Gamma attribute manual parameter

【Syntax】

 typedef struct _ISP_LCAC_MANUAL_ATTR_S {
  CVI_U16 DePurpleCrGain;
  CVI_U16 DePurpleCbGain;
  CVI_U8 DePurepleCrWgt0;
  CVI_U8 DePurepleCbWgt0;
  CVI_U8 DePurepleCrWgt1;
  CVI_U8 DePurepleCbWgt1;
  CVI_U8 EdgeCoringBase;
  CVI_U8 EdgeCoringAdv;
} ISP_LCAC_MANUAL_ATTR_S;

【Member】

Member

Description

DePurpleCrGain

R channel purple fringing correction gain

Value range: [0x0, 0xfff]

Data type: CVI_U16

DePurpleCbGain

B channel purple fringing correction gain

Value range: [0x0, 0xfff]

Data type: CVI_U16

DePurepleCrWgt0

Long Frame R Channel Corrected Intensity Blend Weights

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurepleCbWgt0

Long Frame B Channel Corrected Intensity Blend Weights

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurepleCrWgt1

Short frame R channel corrected intensity blend weights

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurepleCbWgt1

Short frame B channel corrected intensity blend weights

Value range: [0x0, 0x40]

Data type: CVI_U8

EdgeCoringBase

Noise Suppression Control for Base Edge Detection

Value range: [0x0, 0xff]

Data type: CVI_U8

EdgeCoringAdv

Noise suppression control for Advance edge detection

Value range: [0x0, 0xff]

Data type: CVI_U8

【Note】

None.

【Related Data Type and Interface】

28.3.3. ISP_LCAC_AUTO_ATTR_S

【Description】

Gamma attribute automatic parameter

【Syntax】

 typedef struct _ISP_LCAC_AUTO_ATTR_S {
  CVI_U16 DePurpleCrGain[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U16 DePurpleCbGain[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U8 DePurepleCrWgt0[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U8 DePurepleCbWgt0[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U8 DePurepleCrWgt1[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U8 DePurepleCbWgt1[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U8 EdgeCoringBase[ISP_AUTO_ISO_STRENGTH_NUM];
  CVI_U8 EdgeCoringAdv[ISP_AUTO_ISO_STRENGTH_NUM];
} ISP_LCAC_AUTO_ATTR_S;

【Member】

Member

Description

DePurpleCrGain

R channel purple fringing correction gain

Value range: [0x0, 0xfff]

Data type: CVI_U16

DePurpleCbGain

B channel purple fringing correction gain

Value range: [0x0, 0xfff]

Data type: CVI_U16

DePurepleCrWgt0

Long Frame R Channel Corrected Intensity Blend Weights

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurepleCbWgt0

Long Frame B Channel Corrected Intensity Blend Weights

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurepleCrWgt1

Short frame R channel corrected intensity blend weights

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurepleCbWgt1

Short frame B channel corrected intensity blend weights

Value range: [0x0, 0x40]

Data type: CVI_U8

EdgeCoringBase

Noise Suppression Control for Base Edge Detection

Value range: [0x0, 0xff]

Data type: CVI_U8

EdgeCoringAdv

Noise suppression control for Advance edge detection

Value range: [0x0, 0xff]

Data type: CVI_U8

【Note】

None.

【Related Data Type and Interface】

28.3.4. ISP_LCAC_ATTR_S

【Description】

Gamma attribute parameter

【Syntax】

 typedef struct _ISP_LCAC_ATTR_S {
  CVI_BOOL Enable;
  ISP_OP_TYPE_E enOpType;
  CVI_U8 UpdateInterval;
  CVI_U8 TuningMode;
  CVI_U8 DePurpleCrStr0;
  CVI_U8 DePurpleCbStr0;
  CVI_U8 DePurpleCrStr1;
  CVI_U8 DePurpleCbStr1;
  CVI_U8 FilterTypeBase;
  CVI_U8 EdgeGainBase0;
  CVI_U8 EdgeGainBase1;
  CVI_U8 EdgeStrWgtBase;
  CVI_U8 DePurpleStrMaxBase;
  CVI_U8 DePurpleStrMinBase
  CVI_U8 FilterScaleAdv;
  CVI_U8 LumaWgt;
  CVI_U8 FilterTypeAdv;
  CVI_U8 EdgeGainAdv0;
  CVI_U8 EdgeGainAdv1;
  CVI_U8 EdgeStrWgtAdvG;
  CVI_U8 DePurpleStrMaxAdv;
  CVI_U8 DePurpleStrMinAdv;
  ISP_LCAC_GAUSS_COEF_ATTR_S EdgeWgtBase;
  ISP_LCAC_GAUSS_COEF_ATTR_S EdgeWgtAdv;
  ISP_LCAC_MANUAL_ATTR_S stManual;
  ISP_LCAC_AUTO_ATTR_S stAuto;
} ISP_LCAC_ATTR_S;

【Member】

Member

Description

Enable

LCAC module enable

Value range: [0, 1]

Data type: CVI_BOOL

enOpType

job type

OP_TYPE_AUTO: automatic mode

OP_TYPE_MANUAL: manual mode

UpdateInterval

Affects the parameter update terval, the larger the value, the slower the screen changes and the better the performance

Value range: [0x0, 0xff]

Data type: CVI_U8

TuningMode

Threshold for edge detection. The smaller the value, the more regions are judged as edges

Value range: [0x0, 0x6]

Data type: CVI_U8

DePurpleCrStr0

Long frame R channel correction strength

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurpleCbStr0

Long Frame B Channel Correction Intensity

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurpleCrStr1

Short frame R channel correction strength

Value range: [0x0, 0x40]

Data type: CVI_U8

DePurpleCbStr1

Short frame B channel correction strength

Value range: [0x0, 0x40]

Data type: CVI_U8

FilterTypeBase

Filter selection. The larger the value, the stronger the purple fringing strength

Value range: [0x0, 0x3]

Data type: CVI_U8

EdgeGainBase0

Intensity gain for long frame edge detection

Value range: [0x0, 0x1c]

Data type: CVI_U8

EdgeGainBase1

Intensity Gain for Short Frame Edge Detection

Value range: [0x0, 0x23]

Data type: CVI_U8

EdgeStrWgtBase

Base channel edge detection weight

Value range: [0x0, 0x10]

Data type: CVI_U8

DePurpleStrMaxBase

Base Upper limit for de-fringing intensity

Value range: [0x0, 0x80]

Data type: CVI_U8

DePurpleStrMinBase

Base Lower limit for de-fringing intensity

Value range: [0x0, 0x80]

Data type: CVI_U8

FilterScaleAdv

filter scale parameter

Value range: [0x0, 0xf]

Data type: CVI_U8

LumaWgt

Luma Blend Weight

Value range: [0x0, 0x1ff]

Data type: CVI_U16

FilterTypeAdv

filter selection. The larger the value, the stronger the purple fringing strength

Value range: [0x0, 0x40]

Data type: CVI_U8

EdgeGainAdv0

Intensity gain for long frame edge detection

Value range: [0x0, 0x1c]

Data type: CVI_U8

EdgeGainAdv1

Intensity Gain for Short Frame Edge Detection

Value range: [0x0, 0x23]

Data type: CVI_U8

EdgeStrWgtAdvG

Advance G channel edge detection weights

Value range: [0x0, 0x10]

Data type: CVI_U8

DePurpleStrMaxAdv

Advance Upper limit of the intensity of purple fringing

Value range: [0x0, 0xff]

Data type: CVI_U8

DePurpleStrMinAdv

Advance The lower limit of the intensity of purple fringing

Value range: [0x0, 0xff]

Data type: CVI_U8

EdgeWgtBase

Control the degree of purple fringing according to the edge strength, and determine the weight curve of the fusion of the purple fringing result and the original image

EdgeWgtAdv

Control the degree of purple fringing according to the edge strength, and determine the weight curve of the fusion of the purple fringing result and the original image

stManual

Manual Mode parameter Properties

stAuto

Auto Mode parameter Properties

【Note】

None.

【Related Data Type and Interface】