List of Spatial Filters

The following is a list of the predefined spatial filters that can be applied using the L_SpatialFilterBitmap function:

Value

Meaning

FLT_EMBOSS_N
FLT_EMBOSS_NE
FLT_EMBOSS_E
FLT_EMBOSS_SE
FLT_EMBOSS_S
FLT_EMBOSS_SW
FLT_EMBOSS_W
FLT_EMBOSS_NW

[#define] Creates an image with an embossed appearance. (This is used for artistic effect, but is listed here because it is one of the predefined filters.) Choose the appropriate value for the direction of the effect.

FLT_GRADIENT_N
FLT_GRADIENT_NE
FLT_GRADIENT_E
FLT_GRADIENT_SE
FLT_GRADIENT_S
FLT_GRADIENT_SW
FLT_GRADIENT_W
FLT_GRADIENT_NW

[#define] Detects edges using a Gradient directional filter. All pixels not on the detected edges are changed to black. Choose the appropriate value for the direction of the effect.

FLT_LAPLACE_1
FLT_LAPLACE_2
FLT_LAPLACE_3
FLT_LAPLACE_DIAG
FLT_LAPLACE_HORZ
FLT_LAPLACE_VERT

[#define] Applies Laplacian line detection. There are three omnidirectional filters and three bi-directional ones. All pixels not on the detected lines are changed to black.

FLT_SOBEL_HORZ
FLT_SOBEL_VERT

[#define] Applies Sobel edge detection. All pixels not on the detected edges are changed to black. (The usage is the same as Prewitt, but the algorithm is different.) Choose the appropriate value for horizontal or vertical detection.

FLT_PREWITT_HORZ
FLT_PREWITT_VERT

[#define] Applies Prewitt edge detection. All pixels not on the detected edges are changed to black. (The usage is the same as Sobel, but the algorithm is different.) Choose the appropriate value for horizontal or vertical detection.

FLT_SHIFTDIFF_DIAG
FLT_SHIFTDIFF_HORZ
FLT_SHIFTDIFF_VERT

[#define] Applies shift-and-difference edge detection. All pixels not on the detected edges are changed to black. Choose the appropriate value for diagonal, horizontal, or vertical detection.

FLT_LINESEG_HORZ
FLT_LINESEG_VERT
FLT_LINESEG_LTOR
FLT_LINESEG_RTOL

[#define] Applies line segment line detection. You can use this filter to find line discontinuities in an image. All pixels not on the detected line segments are changed to black. Choose the appropriate value for horizontal, vertical, left-to-right diagonal, or right-to-left diagonal detection.