Header

Image handling


Detailed Description

Functions for capturing, displaying and saving images.


Typedefs

typedef void GXAPI FPS_EVFUNC (int event, int param1, int param2, void *uparam)
 The event function is a callback function which is called during capture.

Functions

static int fps_capture (gxHANDLE handle, int timeout, int quality, int mode, int fingerlist)
 Scan fingers from captured images.
static int fps_capture_start (gxHANDLE handle, int timeout, int quality, int mode, int fingerlist, int *reqid)
 Starts the finger image capturing process in asynchronous mode.
static int fps_capture_getstatus (gxHANDLE handle, int reqid, int *status)
 Returns the state of an image capture process started with the fps_capture_start() function.
static int fps_capture_stop (gxHANDLE handle)
 Stops the capture process started with the fps_capture_start() or the fps_capture() function before the timeout is elapsed.
static int fps_capture_wait (gxHANDLE handle, int reqid)
 Ends the capture process started with the fps_capture_start() function.
static int fps_capture_preview (gxHANDLE handle, int windowid)
 Captures a preview image.
static int fps_getimage (gxHANDLE handle, int smode, int position, int type, gxVARIANT *img)
 Returns a captured image.
static int fps_saveimage (gxHANDLE handle, int smode, int position, int type, const wchar_t *filename, int filetype)
 Saves an image to a file (Unicode version).
static int fps_saveimagea (gxHANDLE handle, int smode, int position, int type, const char *filename, int filetype)
 Saves an image to a file (ASCII version).
static int fps_drawimage (gxHANDLE handle, int smode, int position, int type, HDC hdc, int x, int y, int xsize, int ysize, gxRCT *frame)
 Displays an image (WIN32 function).


Typedef Documentation

typedef void GXAPI FPS_EVFUNC(int event, int param1, int param2, void *uparam)

The event function is a callback function which is called during capture.

The event function of the FPS system can be set with fps_seteventfunction().

Parameters:
event The event Id.
param1 The actual scan mode if it is meaningful.
param2 The actual finger position if it is meaningful.
uparam User parameter.


Function Documentation

static int fps_capture ( gxHANDLE  handle,
int  timeout,
int  quality,
int  mode,
int  fingerlist 
) [static]

Scan fingers from captured images.

To set a callback function to inform the state of the capturing call the fps_seteventfunction() function. The captured images are stored in an inside array. The image handling functions are part of the api. (draw, save, recognize...)

Parameters:
handle Handle of the fpsapi module.
timeout Reading timeout, the function returns at timeout.
quality Quality threshold, the function returns when the quality of all fingers reaches the threshold.
mode Scan mode, FPS_IMPRESSION_TYPE.
fingerlist The finger list, having the following format: (hex) 'h-imrlts' The topmost digit 'h' (bits 28-31) represent the hand which could be:
  • 1 for left hand,
  • 2 for right hand,
  • 3 for both hands.
Digits 'i' (bits 20-23), 'm' (bits 16-19), 'r' (bits 12-15) and 'l' (bits 8-11) represent the fingers (index, middle, ring, little). Digits 't' (bits 4-7) and 's' (bits 0-3) represent the left and right thumbs. When thumbs are specified together with a finger and 'both hands' than 't' and 's' represent the fingers of both hands. The value of the finger and thumb digits could be a value of the FPS_PRESENCE enumeration.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_capture_start ( gxHANDLE  handle,
int  timeout,
int  quality,
int  mode,
int  fingerlist,
int *  reqid 
) [static]

Starts the finger image capturing process in asynchronous mode.

See fps_capture() for details. Only one capture can be started at a time. The fps_capture_getstatus() or the fps_capture_wait() functions must be called in order the system to call the Event function. (see fps_seteventfunction() )

Parameters:
handle Handle of the fpsapi module.
timeout Reading timeout, the function returns at timeout.
quality Quality threshold, the function returns when the quality of all fingers reaches the threshold.
mode Scan mode, FPS_IMPRESSION_TYPE.
fingerlist The finger list, having the following format: (hex) 'h-imrlts' The topmost digit 'h' (bits 28-31) represent the hand which could be:
  • 1 for left hand,
  • 2 for right hand,
  • 3 for both hands.
Digits 'i' (bits 20-23), 'm' (bits 16-19), 'r' (bits 12-15) and 'l' (bits 8-11) represent the fingers (index, middle, ring, little). Digits 't' (bits 4-7) and 's' (bits 0-3) represent the left and right thumbs. When thumbs are specified together with a finger and 'both hands' than 't' and 's' represent the fingers of both hands. The value of the finger and thumb digits could be a value of the FPS_PRESENCE enumeration.
reqid Id for the getstatus and the wait functions.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_capture_getstatus ( gxHANDLE  handle,
int  reqid,
int *  status 
) [static]

Returns the state of an image capture process started with the fps_capture_start() function.

If an internal event occurred this function calls the Event function.

Parameters:
handle Handle of the fpsapi module.
reqid Id for the capture. The fps_capture_start() returned this value.
status Buffer for the result. The value of the result is the elapsed time in percent of timeout, it can be negative when the capture is in preprocess state.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_capture_stop ( gxHANDLE  handle  )  [static]

Stops the capture process started with the fps_capture_start() or the fps_capture() function before the timeout is elapsed.

The fps_capture_wait() function must be called in asynchronous mode anyway.

Parameters:
handle Handle of the fpsapi module.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_capture_wait ( gxHANDLE  handle,
int  reqid 
) [static]

Ends the capture process started with the fps_capture_start() function.

If there are internal events waiting for report this function calls the Event function.

Parameters:
handle Handle of the fpsapi module.
reqid Id of the capture returned by the fps_capture_start().
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_capture_preview ( gxHANDLE  handle,
int  windowid 
) [static]

Captures a preview image.

The preview image is a small resolution real-time captured image. For preview light control the freerun_mode property must contain the FPS_FRMODE_PREVIEWLIGHT value.

Parameters:
handle Handle of the fpsapi module.
windowid RFU.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_getimage ( gxHANDLE  handle,
int  smode,
int  position,
int  type,
gxVARIANT img 
) [static]

Returns a captured image.

The Fingerprint Scanner system has several functions for working with the captured images. In special cases user functions can be used that are not supported by the system. This function references the image and returns a pointer to the image. The user function can reach the image data through the pointer. After the process the gx_unrefvariant() function must be called in order to decrease the reference counter.

Parameters:
handle Handle of the fpsapi module.
smode The actual scan mode of the image. The possible values are defined in FPS_IMPRESSION_TYPE enumeration.
position The finger position. The possible values are defined in the FPS_POSITION enumeration.
type The type of the image. The possible values are defined in the FPS_IMAGE_TYPE enumeration. If the type is FPS_IT_PREVIEW the smode and position parameters have no meanings.
img Buffer for the image reference.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_saveimage ( gxHANDLE  handle,
int  smode,
int  position,
int  type,
const wchar_t *  filename,
int  filetype 
) [static]

Saves an image to a file (Unicode version).

Parameters:
handle Handle of the fpsapi module.
smode The actual scan mode of the image. The possible values are defined in FPS_IMPRESSION_TYPE enumeration.
position The finger position. The possible values are defined in the FPS_POSITION enumeration.
type The type of the image. The possible values are defined in the FPS_IMAGE_TYPE enumeration. If the type is FPS_IT_PREVIEW the smode and position parameters have no meanings.
filename The name of the file where to save the image.
filetype File type. The currently supported file types are defined in gximage.h.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_saveimagea ( gxHANDLE  handle,
int  smode,
int  position,
int  type,
const char *  filename,
int  filetype 
) [static]

Saves an image to a file (ASCII version).

Parameters:
handle Handle of the fpsapi module.
smode The actual scan mode of the image. The possible values are defined in FPS_IMPRESSION_TYPE enumeration.
position The finger position. The possible values are defined in the FPS_POSITION enumeration.
type The type of the image. The possible values are defined in the FPS_IMAGE_TYPE enumeration. If the type is FPS_IT_PREVIEW the smode and position parameters have no meanings.
filename The name of the file where to save the image.
filetype File type. The currently supported file types are defined in gximage.h.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().

static int fps_drawimage ( gxHANDLE  handle,
int  smode,
int  position,
int  type,
HDC  hdc,
int  x,
int  y,
int  xsize,
int  ysize,
gxRCT frame 
) [static]

Displays an image (WIN32 function).

Parameters:
handle Handle of the fpsapi module.
smode The actual scan mode of the image. The possible values are defined in FPS_IMPRESSION_TYPE enumeration.
position The finger position. The possible values are defined in the FPS_POSITION enumeration.
type The type of the image. The possible values are defined in the FPS_IMAGE_TYPE enumeration. If the type is FPS_IT_PREVIEW the smode and position parameters have no meanings.
hdc Handle to the device context.
x Left side of the draw area.
y Upper side of the draw area.
xsize Horizontal size of the draw area.
ysize Vertical size of the draw area.
frame Frame of the area on the image to display.
Returns:
On error false is returned and the error code/string in the GX system is set appropriately. ( see gx_geterror() )

References gx_call().


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