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BLANKPAGEDETECTOROPTIONS

typedef struct BLANKPAGEDETECTOROPTIONS 
{ 
   L_UINT uStructSize; 
   L_BOOL bIsBlank; 
   L_UINT uAccuracy; 
   PAGEMARGINS PMargins; 
   L_UINT uSensitivity; 
   L_UINT uMinimumTextSize; 
   L_UINT uFlags; 
} BLANKPAGEDETECTOROPTIONS, * pBLANKPAGEDETECTOROPTIONS;

The BLANKPAGEDETECTOROPTIONS structure provides options to be used in detecting whether an image is a blank page.

Members

uStructSize

Size of this structure in bytes, for versioning. Use the sizeof() operator to calculate this value.

bIsBlank

The image status indicating whether it is a blank page or not. Possible values are:

Value	Meaning
True	Blank page.
False	Non-blank page.

uAccuracy

The accuracy percentage of the result. Possible values range from 0 to 10000. This value is divided internally by the value 100.

PMargins

A structure that contains information about excluded margins. Pass NULL as no margins to exclude.

uSensitivity

Determines the sensitivity of the blank page detection, based on the amount of black pixels in the image. Possible values range from 0 to 100.

uMinimumTextSize

The minimum text height, all objects with height less than this value will be considered noisy objects.

uFlags

Flags that indicate how to consider blank pages and the function behavior. You can combine values when appropriate by using a bitwise OR (|). Possible values are:

Value	Meaning
Consider noisy page as a blank page:
BLANK_DETECT_EMPTY	[0x00000000] A page must be totally blank.
BLANK_DETECT_NOISY	[0x00000001] A page may have some noise. This is the default value.
Consider page which bleeds through its other side as a blank page:
BLANK_NOT_BLEED_THROUGH	[0x00000000] Don't ignore bleed through from the page.
BLANK_BLEED_THROUGH	[0x00000010] Ignore bleed through from the page. This is the default value.
Consider lined page as a blank page:
BLANK_DONT_DETECT_LINES	[0x00000000] Don't consider lined page as a blank page. This is the default value.
BLANK_DETECT_LINES	[0x00000100] Consider lined page as a blank page.
Ignoring blank spaces around the page edges:
BLANK_DONT_USE_ACTIVE_AREA	[0x00000000] Don't ignore blank spaces around the page edges. This is the default value.
BLANK_USE_ACTIVE_AREA	[0x00001000] Ignore blank spaces around the page edges.
Use default margins or user-specified margins:
BLANK_DEFAULT_MARGIN	[0x00000000] Use default margins, which are computed automatically by the function based on the page dimensions. This is the default value.
BLANK_USER_MARGIN	[0x00010000] Use the user-specified margins, which are specified in `PMargins`.

Comments

pBLANKPAGEDETECTOROPTIONS is a pointer to BLANKPAGEDETECTOROPTIONS structure. Generally, where a function parameter type is pBLANKPAGEDETECTOROPTIONS, you can declare a BLANKPAGEDETECTOROPTIONS variable, update the structure's fields, and pass the variable's address in the parameter. Declaring a pBLANKPAGEDETECTOROPTIONS variable is necessary only if your program requires a pointer.

For various reasons, documents being scanned can contain a significant number of blank pages. Disk storage space for the scanned items can be reduced if such pages can be removed before the documents are stored. These options detect whether a page is blank and returns an accuracy value. It can detect blank pages (despite noise, bleed-through, or lines) with high precision and speed.

The structure is used by: