MimDifferential

Board	Supported
Host System	Yes
V4L2	Yes
Clarity UHD	Yes
Concord PoE	No
GenTL	Yes
GevIQ	Yes
GigE Vision	Yes
Indio	No
Iris GTX	Yes
Radient eV-CL	Yes
Rapixo CL	Yes
Rapixo CoF	Yes
Rapixo CXP	Yes
USB3 Vision	Yes

Perform a differential operation.

Syntax

void MimDifferential(
    AIL_ID     Drv1ImageBufIdOrFilterContextImId,  //in
    AIL_ID     SrcOrDrv2ImageBufId,                //in
    AIL_ID     SrcOrDrv3ImageBufId,                //in
    AIL_ID     Drv4ImageBufId,                     //in
    AIL_ID     Drv5ImageBufId,                     //in
    AIL_ID     Dst1ImageBufId,                     //out
    AIL_ID     Dst2ImageBufId,                     //out
    AIL_DOUBLE Param,                              //in
    AIL_INT64  Operation,                          //in
    AIL_INT64  ControlFlag                         //in
)

Description

This function performs a differential operation on an image, based on either automatically calculated or specified derivative images. This function can be used, for example, to calculate the gradient magnitude and orientation (angle) of edges in an image, or to sharpen an image.

You can have MimDifferential automatically calculate the required derivatives (in X and Y) of the source image by passing a linear IIR filter image processing context (previously allocated using MimAlloc with M_LINEAR_FILTER_IIR_CONTEXT). MimDifferentialcalculates the derivatives using IIR filters. You can partially define how the derivatives are calculated by configuring the IIR filter image processing context using MimControl. MimDifferential ignores the M_FILTER_OPERATION setting.

You can have MimDifferential use precalculated derivatives by passing derivative image buffers: most operations require one image buffer with the derivative in X, and another with the derivative in Y (for the first derivatives, this is synonymous with passing the vertical and horizontal edge detection images, respectively). Passing precalculated derivatives is useful if you need to calculate the derivatives using a specific filter operation (for example, using MimConvolvewith a predefined FIR filter or a custom kernel), or use the derivatives with multiple functions (in which case, it is more efficient to calculate the derivatives only once).

Note: Note that some operations require the first derivative images, while others require the second derivative images.

Parameters

Drv1ImageBufIdOrFilterContextImId (in, AIL_ID)

Specifies the identifier of an image buffer that stores a derivative, or a linear IIR filter context. The image buffer must not have a region of interest (ROI) associated with it. Specifying an image buffer with an ROI will cause an error.

SrcOrDrv2ImageBufId (in, AIL_ID)

Specifies the identifier of an image buffer that stores the source image, or a derivative. The image buffer must not have a region of interest (ROI) associated with it. Specifying an image buffer with an ROI will cause an error.

SrcOrDrv3ImageBufId (in, AIL_ID)

Specifies the identifier of an image buffer that stores the source image (for a sharpening operation), or a derivative. The image buffer must not have a region of interest (ROI) associated with it. Specifying an image buffer with an ROI will cause an error.

Drv4ImageBufId (in, AIL_ID)

Reserved for future expansion and must be set to M_NULL.

Drv5ImageBufId (in, AIL_ID)

Reserved for future expansion and must be set to M_NULL.

Dst1ImageBufId (out, AIL_ID)

Specifies the identifier of the first destination image buffer. The image buffer must not have a region of interest (ROI) associated with it. Specifying an image buffer with an ROI will cause an error.

Dst2ImageBufId (out, AIL_ID)

Specifies the identifier of the second destination image buffer. The image buffer must not have a region of interest (ROI) associated with it. Specifying an image buffer with an ROI will cause an error.

Param (in, AIL_DOUBLE)

Specifies an attribute of the operation to perform. Set this parameter to M_DEFAULT if not used.

Operation (in, AIL_INT64)

Specifies the differential operation to perform.

ControlFlag (in, AIL_INT64)

Specifies a control setting for the operation to perform. Set this parameter to M_DEFAULT if not used.

Parameter Associations

For specifying the differential operation

Set unused source and destination parameters to M_NULL. Set other unused parameters to M_DEFAULT.

---

M_GRADIENT

Performs a gradient operation.

Drv1ImageBufIdOrFilterContextImId - Image buffer ID

Specifies the identifier of a float or signed image buffer, indicating the first derivative in X.

Drv1ImageBufIdOrFilterContextImId - Linear IIR filter context ID

Specifies the identifier of a linear IIR filter context (M_LINEAR_FILTER_IIR_CONTEXT).

---

M_GRADIENT_SQR

Performs a square gradient operation.

Drv1ImageBufIdOrFilterContextImId - Image buffer ID

Specifies the identifier of a float or signed image buffer, indicating the first derivative in X.

Drv1ImageBufIdOrFilterContextImId - Linear IIR filter context ID

Specifies the identifier of a linear IIR filter context (M_LINEAR_FILTER_IIR_CONTEXT).

---

M_LAPLACIAN

Performs a Laplacian operation.

Drv1ImageBufIdOrFilterContextImId - Image buffer ID

Specifies the identifier of a float or signed image buffer, indicating the second derivative in X.

Drv1ImageBufIdOrFilterContextImId - Linear IIR filter context ID

Specifies the identifier of a linear IIR filter context (M_LINEAR_FILTER_IIR_CONTEXT).

---

M_SHARPEN

Performs a sharpening operation.

Drv1ImageBufIdOrFilterContextImId - Image buffer ID

Specifies the identifier of a float or signed image buffer, indicating the second derivative in X.

Value	Description
Value > 0.0	Specifies the sharpening value.

Drv1ImageBufIdOrFilterContextImId - Linear IIR filter context ID

Specifies the identifier of a linear IIR filter context (M_LINEAR_FILTER_IIR_CONTEXT).

Value	Description
M_DEFAULT	Specifies that Aurora Imaging Library will establish an appropriate sharpening value.
Value > 0.0	Specifies the sharpening value.
M_DEFAULT	Specifies to perform the sharpening operation.
M_PREPROCESS	Specifies to preprocesses the linear IIR filter context explicitly. Note, if not called explicitly, Aurora Imaging Library performs this operation automatically upon the first call to MimDifferential.

Remarks

In-place processing is supported, but the source and destination image buffers cannot partially overlap (a situation that can only occur when using child buffers).