Solved

# distance between two pixels using VB.

Posted on 2001-07-18
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Hi,
I have a BW scanned image that is saved as a bmp, basically I want to figure out it's length by measuring the top-most black pixel and the bottom pixel.  How do I find these pixels?  I also would like to find the width at a certain number of inches, pixels, or whatever down the image.  How do I do this also?  I figure it would be easy if I started at the top left pixel and scaned row by row till I found a black one but I have no idea how to do this.  Can someone help me?

Aaron
0
Question by:Cide

LVL 22

Accepted Solution

rspahitz earned 150 total points
ID: 6296056
Point Method

Returns, as a long integer, the red-green-blue (RGB) color of the specifiedpoint on a Form or PictureBox. Doesn't supportnamed arguments.

Syntax

object.Point(x, y)

--
Use a loop something like this:

for y=0 to Picture1.height
for x=0 to Picture1.width
if Picture1.Point(x,y) = vbBlack then
msgbox "Found it at x,y= " & x & "," & y, vbokonly
y = Picture1.height ' force exit of the row loop
exit for
end if
next x
next y

0

LVL 8

Expert Comment

ID: 6296575
Hi!

Here's a file over the net for you:

Description: I just made a couple changes to this.I am new at programming so this is my first shot so i hope i don't blow it:) This program lets you open a picture file and it tells you the height and width of the picture in pixels. I think this would come in very handy in making webpages so you'll know the exact dimensions of the pic. If it is really useless let me know. Thx

That's it!

0

LVL 5

Expert Comment

ID: 6297083
Note about rspahitz's code. Change the picbox's scalemode to pixels. It'll run about 225 (15x15) times faster that way. Also, you'll need a backwards loop to search up from the bottom. Same code, but with two changes:

for y=Picture1.height to 0 step -1

y = 0 ' force exit of the row loop

KDL
0

LVL 5

Expert Comment

ID: 6297088
To get the width, just pick a row (second parameter of Point) to select points from and search across (inner For-Next loop). Then do the same on the same row but look backwards from the other end.
0

LVL 22

Expert Comment

ID: 6299282
0

Author Comment

ID: 6299479
Wow works like a charm thanks guys!

Kdivad thnaks additionally for your extra help, went so much faster with your "tweaks".  If you want some points I can put then on a sperate question just ask me.
0

LVL 5

Expert Comment

ID: 6299608
rspahitz,
We all have to forget something sometimes. Gives the rest of us a chance to brag a bit. <grin>

Cide,

Later,
KDL
0

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