Is_Initimagequeue - THORLABS DCU223x Operation Manual And Sdk

DCx Cameras

4.3.62 is_InitImageQueue

USB 2.0
USB 3.0
Syntax
INT is_InitImageQueue (HIDS hCam, INT nMode)
Description
is_InitImageQueue() enables the queue mode for existing image memory sequences. New images will be
added to the end of the queue on arrival (FIFO principle). The image memory sequence has to be created with
is_AddToSequence()
query the pointer and sequence ID of the first (i.e. oldest) image in the sequence.
Note
Image memory sequences can also be used without queue mode. In this case the current image memory has to be
queried with
is_GetActSeqBuf()
frame rates it may happen that additional images arrive between the frame event and accessing/locking the
memory. The images arriving in this period will be skipped when you query the current image.
When the queue mode is used (is_InitImageQueue()), however, you can be sure to always receive the oldest
image which has not yet been queried. In addition, image memories are automatically locked immediately after
receiving the image. This prevents images from being overwritten when very high frame rates and few image
memories are used.
Input parameters
hCam
nMode
Return values
IS_INVALID_CAMERA_HANDLE
IS_INVALID_PARAMETER
IS_NO_SUCCESS
IS_SUCCESS
Related functions
is_ExitImageQueue()
is_WaitForNextImage()
is_AddToSequence()
Example
// A previously initialized camera continuously captures images
// until a timeout or transfer error occurs.
// Note: image memories have to be allocated before this
is_InitImageQueue (m_hCam, 0);
INT nMemID = 0;
char *pBuffer = NULL;
while (IS_SUCCESS == is_WaitForNextImage(m_hCam, 1000, &pBuffer, &nMemID))
{
is_SaveImageMem (m_hCam, "image.bmp", pBuffer, nMemID);
is_UnlockSeqBuf (m_hCam, nMemID, pBuffer);
}
is_ExitImageQueue (m_hCam);
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USB 2.0
USB 3.0
prior to calling is_InitImageQueue(). With
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on every frame event. Disadvantage of this proceeding is that at very high
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is_WaitForNextImage()
Camera handle
Queue mode. Currently only nMode = 0 is supported.
Invalid camera handle
One of the submitted parameters is outside the valid
range or is not supported for this sensor or is not
available in this mode.
General error message
Function executed successfully
you can
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