References ▼
typedef struct _CONTOURFILTERDLGPARAMS{L_UINT uStructSize;pBITMAPHANDLE pBitmap;L_BOOL bZoomToFit;L_INT16 nThreshold;L_INT16 nDeltaDirection;L_INT16 nMaxError;L_INT nOption;L_UINT32 uOptionFlags;L_UINT32 uDlgFlags;LTCOMMDLGHELPCB pfnHelpCallback;L_VOID *pHelpCallBackUserData;} CONTOURFILTERDLGPARAMS,* LPCONTOURFILTERDLGPARAMS;
The CONTOURFILTERDLGPARAMS structure provides information used to initialize the dialog box created by the L_DlgContourFilter function. After the user closes the dialog box, this structure is updated with information about the user's selections.
Size of this structure, in bytes. Use the sizeof operator to calculate this value.
Pointer to the bitmap handle that references the bitmap used for preview or processing.
Flag that indicates the initial zoom level for previewing the image. Possible values are:
| Value | Meaning |
|---|---|
| TRUE | Set the initial zoom level to "Zoom to fit". |
| FALSE | Set the initial zoom level to "Normal (1:1)". |
Threshold of the gradient magnitude. Values below this will be considered as background, and will be set to 0. Values can be from 1 to 254. A lower threshold provides a better quality image.
Maximum angle for the thinning algorithm. Values can be from 1 to 64.
Maximum error for approximation algorithm. Values can be from 0 to 255.
Flag that controls the resulting image. This value tells the method what process to complete before returning. Possible values are:
| Value | Meaning |
|---|---|
| CONTOUR_THIN | [0] return after the thinning algorithm |
| CONTOUR_LINK_BLACKWHITE | [1] return after contour linking, using only black and white |
| CONTOUR_LINK_GRAY | [2] return after contour linking, using 256 grayscale |
| CONTOUR_LINK_COLOR | [3] return after contour linking, using colors |
| CONTOUR_APPROX_COLOR | [4] return after line segment approximation, using colors |
Values that indicate which options will be available in the Contour Option dropdown box. Possible values are:
| Value | Meaning |
|---|---|
| DLG_CONTOURFILTER_SHOW_OPTION_THIN | [0x00000001] the return after thinning option is available. |
| DLG_CONTOURFILTER_SHOW_OPTION_LINK_BW | [0x00000002] the return after contour linking using only black and white option is available |
| DLG_CONTOURFILTER_SHOW_OPTION_LINK_GRAY | [0x00000004] the return after contour linking using 256 grayscale options is available. |
| DLG_CONTOURFILTER_SHOW_OPTION_LINK_COLOR | [0x00000008] the return after contour linking using colors option is available. |
| DLG_CONTOURFILTER_SHOW_OPTION_APPROX_COLOR | [0x00000010] the return after line segment approximation option is available. |
| DLG_CONTOURFILTER_SHOW_OPTION_ALL | [0x0000001F] ALL the options above available. |
User interface flags for this dialog, which determine the layout and action of the dialog. Possible values are:
| Value | Meaning |
|---|---|
| DLG_CONTOURFILTER_AUTOPROCESS | [0x00000001] process the image on OK. The pBitmap member of this structure should contain a valid bitmap. |
| DLG_CONTOURFILTER_SHOW_CONTEXTHELP | [0x00000002] dialog should contain a context sensitive help icon. |
| DLG_CONTOURFILTER_SHOW_PREVIEW | [0x00000004] show a preview of the image in the dialog. The pBitmap member of this structure should contain a valid bitmap. |
| DLG_CONTOURFILTER_SHOW_TOOL_ZOOMLEVEL | [0x00000008] show the "Zoom to fit" and "Zoom Normal" toolbar buttons. The DLG_CONTOURFILTER_SHOW_PREVIEW flag must be set in order to show these buttons. |
| DLG_CONTOURFILTER_SHOW_OPTION | [0x00000010] show the Contour Option. |
| DLG_CONTOURFILTER_SHOW_THRESHOLD | [0x00000020] show the Threshold option. |
| DLG_CONTOURFILTER_SHOW_DELTADIRECTION | [0x00000040] show the Delta Direction option. |
| DLG_CONTOURFILTER_SHOW_MAXIMUMERROR | [0x00000080] show the Maximum Error option. |
| DLG_CONTOURFILTER_SHOW_APPLY | [0x00000800] Show the Apply button in the dialog. The dialog will not apply any effect unless the user presses the Apply button. |
Pointer to an optional help callback function. If you do not wish to provide help to this dialog, use NULL as the value of this parameter. To provide help to this dialog, use the function pointer as the value of this parameter. The callback function must adhere to the prototype described in LTCOMMDLGHELPCB.
Void pointer that you can use to pass one or more additional parameters that the callback function needs. To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID *. The callback function, which receives the address in its own pHelpCallBackUserData parameter, can cast it to a pointer of the appropriate data type to access your variable or structure. If the additional parameters are not needed, you can pass NULL in this parameter.