Detect Blank Page using DLL API

#1 Posted : Thursday, August 9, 2007 4:57:21 AM(UTC)

pbhaskar

Groups: Registered
Posts: 3

Hi,

We are using LeadTools 14.6 DLL API.

We want to detect and remove the blank page. Please provide me support to find the right API and formula.

Regards

Ganesh.

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#2 Posted : Saturday, August 11, 2007 10:50:38 PM(UTC)

Maen Hasan

Groups: Registered, Tech Support
Posts: 1,326

Was thanked: 1 time(s) in 1 post(s)

Hello,

To detect blank pages, you need create a region that consists of a range of white colors. Then check to see how many pixels are NOT(setnot) in this range
If this number is less than .5% of the total number of pixels in the image, we consider the page blank.
You can play with the values for the lower/upper limits and the percentage for different thresholds
The following code shows how to detect blank pages using API programming interface:
+--------------------+
COLORREF lowerColor, upperColor;
L_INT nRet;
L_UINT32 dwArea;

lowerColor = RGB(200, 200, 200);
upperColor = RGB(255, 255, 255);
nRet = L_SetBitmapRgnColorRGBRange(pBitmap, lowerColor, upperColor, L_RGN_SETNOT);
L_GetBitmapRgnArea(pBitmap, &dwArea);
If (dwArea / (ImageWidth * ImageHeight)) < 0.005
// this is a Blank Image
Else
// this is not a Blank Image
+--------------------+

Thanks,
Maen Badwan
LEADTOOLS Technical Support

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Detect Blank Page using DLL API