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USB 2.0 USB 3.0 GigE |
USB 2.0 USB 3.0 GigE |
Syntax
INT is_GetImageHistogram (HIDS hCam,
int nID, INT ColorMode, DWORD* pHistoMem)
Description
is_GetImageHistogram() computes the histogram of the submitted image. The histogram always contains 256 values per channel. For color modes with a bit depth of more than 8 bits, the system evaluates the 8 most significant bits (MSBs).
Input parameters
hCam |
Camera handle |
nID |
Memory ID |
ColorMode |
Color mode of the image with the nID memory ID For a list of all available color formats and the associated input parameters, see the Appendix: Color and memory formats section. |
pHistoMem |
Pointer to a DWORD array The array must be allocated in such a way that it can accommodate 3*256 values for color formats and in raw Bayer mode. In monochrome mode, the array must be able to accommodate 1*256 values. |
Return values
IS_CANT_COMMUNICATE_WITH_DRIVER |
Communication with the driver failed because no driver has been loaded. |
IS_CANT_OPEN_DEVICE |
An attempt to initialize or select the camera failed (no camera connected or initialization error). |
IS_INVALID_COLOR_FORMAT |
Invalid color format |
IS_INVALID_CAMERA_HANDLE |
Invalid camera handle |
IS_INVALID_MEMORY_POINTER |
Invalid pointer or invalid memory ID |
IS_INVALID_PARAMETER |
One of the submitted parameters is outside the valid range or is not supported for this sensor or is not available in this mode. |
IS_IO_REQUEST_FAILED |
An IO request from the uEye driver failed. Possibly the versions of the ueye_api.dll (API) and the driver file (ueye_usb.sys or ueye_eth.sys) do not match. |
IS_NO_SUCCESS |
General error message |
IS_NULL_POINTER |
Invalid array |
IS_SUCCESS |
Function executed successfully |
Related functions
Example
char * pcSource;
INT nIDSource;
is_AllocImageMem (hCam, 256, 256, 24, &pcSource, &nIDSource);
int nX, nY, nBits, nPitch;
is_InquireImageMem (hCam, pcSource, nIDSource, &nX ,&nY, &nBits, &nPitch);
//Create RGB test image
for (int j = 0; j < nY; j++)
{
for (int i = 0; i < nX*3; i += 3)
{
pcSource[i + j*nPitch] = 0; // Blue pixels
pcSource[i + j*nPitch + 1] = i/3; // Green pixels
pcSource[i + j*nPitch + 2] = 255; // Red pixels
}
}
// Create memory for RGB histogram
DWORD bgrBuffer [256*3];
//Create pointer for each histogram color
DWORD * pBlueHisto = bgrBuffer;
DWORD *pGreenHisto = bgrBuffer + 256;
DWORD * pRedHisto = bgrBuffer + 512;
//Retrieve histogram and release memory
is_GetImageHistogram (hCam, nIDSource, IS_CM_RGB8_PACKED, bgrBuffer);
is_FreeImageMem (hCam, pcSource, nIDSource);
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