USB 2.0 USB 3.0 GigE	USB 2.0 USB 3.0 GigE

Syntax

INT is_Blacklevel(HIDS hCam, UINT nCommand, void* pParam, UINT cbSizeOfParam)

Description

is_Blacklevel() controls the black level correction of the camera which might improve the image quality under certain circumstances. By default, the sensor adjusts the black level value for each pixel automatically. If the environment is very bright, it can be necessary to adjust the black level manually.

UI-112x/UI-512x: On models with HDR sensor the is_Blacklevel() function controls the black level when a contrast adjustment is performed.

Fig. 211: Black level correction - Auto

Fig. 212: Black level correction - Auto + offset

Fig. 213: Black level correction with offset only

The nCommand input parameter is used to select the function mode. The pParam input parameter depends on the selected function mode. If you select functions for setting or returning a value, pParam contains a pointer to a variable of the UINT type. The size of the memory area to which pParam refers is specified in the cbSizeOfParam input parameter.

Input parameters

hCam	Camera handle
nCommand IS_BLACKLEVEL_CMD_GET_CAPS Returns the black level feature of the camera (Example 1): •IS_BLACKLEVEL_CAP_SET_AUTO_BLACKLEVEL: The state of the automatic black level can be changed. The flag does not indicate whether the camera is running with auto black level by default or not. For this purpose, use IS_BLACKLEVEL_CMD_GET_MODE_DEFAULT. •IS_BLACKLEVEL_CAP_SET_OFFSET: The offset can be changed. The flag does not indicate whether the camera has set an offset by default or not. For this purpose, use IS_BLACKLEVEL_CMD_GET_OFFSET_DEFAULT. IS_BLACKLEVEL_CMD_GET_MODE_DEFAULT Returns the default black level mode (Example2) IS_BLACKLEVEL_CMD_GET_MODE Returns the current black level mode (Example2) IS_BLACKLEVEL_CMD_SET_MODE Sets the black level mode (Example 2) •IS_AUTO_BLACKLEVEL_OFF: The automatic black level mode is switched off. •IS_AUTO_BLACKLEVEL_ON: The automatic black level mode is switched on. IS_BLACKLEVEL_CMD_GET_OFFSET_DEFAULT Returns the default offset (Example 3) IS_BLACKLEVEL_CMD_GET_OFFSET_RANGE Returns the range of the offset (Example 3) IS_BLACKLEVEL_CMD_GET_OFFSET Returns the current offset (Example 3) IS_BLACKLEVEL_CMD_SET_OFFSET Sets the offset (Example 3)
pParam	Pointer to a function parameter, whose function depends on nCommand.
cbSizeOfParam	Size (in bytes) of the memory area to which pParam refers.

Return values

Example 1

INT nBlacklevelCaps;

nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_GET_CAPS,

                  (void*)&nBlacklevelCaps, sizeof(nBlacklevelCaps));

if (nRet == IS_SUCCESS) {

// The user can changed the state of the auto blacklevel

BOOL bSetAutoBlacklevel = (nBlacklevelCaps & IS_BLACKLEVEL_CAP_SET_AUTO_BLACKLEVEL) != 0;

// The user can change the offset

BOOL bSetBlacklevelOffset = (nBlacklevelCaps & IS_BLACKLEVEL_CAP_SET_OFFSET) != 0;

}

Example 2

INT nMode = IS_AUTO_BLACKLEVEL_OFF;

// Get default blacklevel mode

INT nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_GET_MODE_DEFAULT, (void*)&nMode, sizeof(nMode));

// Get current blacklevel mode

nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_GET_MODE, (void*)&nMode, sizeof(nMode));

// Set new mode (enable auto blacklevel)

nMode = IS_AUTO_BLACKLEVEL_ON;

nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_SET_MODE, (void*)&nMode , sizeof(nMode ));

Example 3

INT nOffset = 0;

// Get default blacklevel offset

INT nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_GET_OFFSET_DEFAULT,

                        (void*)&nOffset, sizeof(nOffset));

// Get offset range

IS_RANGE_S32 nRange;

nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_GET_OFFSET_RANGE, (void*)&nRange, sizeof(nRange));

INT nOffsetMin = nRange.s32Min;

INT nOffsetMax = nRange.s32Max;

INT nOffsetInc = nRange.s32Inc;

// Get current blacklevel offset

nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_GET_OFFSET, (void*)&nOffset, sizeof(nOffset));

// Set new offset

nOffset = 100;

nRet = is_Blacklevel(hCam, IS_BLACKLEVEL_CMD_SET_OFFSET, (void*)&nOffset, sizeof(nOffset));