Getting grayscale values from an image

NickB · June 2013

(Originally posted by Jingsong Wang on 7/26/2006)

I need to read pixel intensity of each line from a grayscale image using IP macro coding. How can I get the intensity of position at position (I, J) ? Thanks.

NickB · June 2013

(Originally posted by Paul on 7/26/2006)

This code snippet will do the trick, and is flexible enough to do all sorts of other things with:


Sub getGsVals()
 Dim i As Integer
 Dim j As Integer

 Dim docId As Integer
 Dim docInfo As IPDOCINFO

 Dim hstStats(10) As Single

 ret = IpDocGet(GETACTDOC, 0, docId)

 ret = IpDocGet(GETDOCINFO, docId, docInfo)

'Create AOI per pixel, iterate through height and width of image
 For i = 0 To docInfo.height
  For j = 0 To docInfo.width
   ipRect.Left = j
   ipRect.Right = j
   ipRect.top = i
   ipRect.bottom = i
   ret = IpAoiCreateBox(ipRect)
'Get histogram stats
'for a 1x1 AOI, hstStats(0), 
'the mean value, will suffice
   ret = IpHstGet(GETSTATS, 0, hstStats(0))
   Debug.Print Str(i) & ", " & Str(j) & _ 
      ": " & Str(hstStats(0))
  Next j
 Next i
End Sub

NickB · June 2013

(Originally posted by KevinR on 7/26/2006)

If you wish to get individual pixel values (rather than statistics for an area/line), take a look at "IpDocGetArea" in the AutoPro help files. This function lets you get areas from an image into an IpBasic array for closer examination.

NickB · June 2013

(Originally posted by Jingsong Wang on 7/26/2006)

Thanks for the solutions. I will try IpDocGetLine as well.

BTW, what is the maximun number of 16-bit greyscale data in an one dimension array within IpBasic? How many arrays I can assign ?

NickB · June 2013

(Originally posted by KevinR on 7/28/2006)

Images are limited to 64K on a side - the frame size limit of ~750MB is usually more constraining.

Declare your images and index the arrays with 'Long' variables to avoid short integer limits of +/-32K.

I believe that arrays can have 5 or more dimensions, although I have _never_ found it necessary to create an array with a dimension greater than 3 for any practical purposes. I haven't run into any limits on the number of arrays you can declare, although if you are looking to create one per line of an image I would strongly recommend creating a 2D array instead.

facesad · September 2013

there are a few methods you can try to get pixel walues, here is sdk you can make use of which provide high-performance image retrieve information slutions to detect and retireve image pixel and other information. quite useful, you can give a try, i hope it is helpful to you.

Getting grayscale values from an image

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