Getting grayscale values from an image

NickB

(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

(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

(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

(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

(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

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.