Compare two image files??

Hi,

is it possible to compare an image file on your Form
and one on a Homepage??

CU

AbsoluteB

How do you mean compare? in size?
if so then you would have to d/l that image and take the size of it (FileLen("C:\wheereveryoudownloadto")) and take the size of the image in your program and if the are = then MsgBox "whatever"

Hope taht's what you meant,
D!m

I'll explain it a lil better now that i have a couple minutes...
D/l the image

Code:

---

Dim iFile As Integer
Dim bBIN As Byte
Inet1.Cancel ' Stops any current operations
Inet1.AccessType = icUseDefault
bBIN = Inet1.OpenURL("www.vb-world.net/images/vbworld.gif", icByteArray)
iFile = FreeFile
Open "C:\vbworld.gif" For Binary Access Write As iFile
Put #iFile, , bBIN
Close iFile

---

Don't forget to add the inet control. (code provided by Matthew Gates on an earlier post)
Then
Get it's size and place it in a textbox or a label.
[CODE]
Text1.Text = FileLen("C:\vbworld.gif")
[CODE]
Then get the image size of the image in your form

Code:

---

Text2.Text = FileLen(app.path & "vbworld.gif")

---

Then under a command button or still in the form load:

Code:

---

If Text1.Text = Text2.Text Then
      MsgBox "The sizes are identical"
Else
      MsgBox "The sizes are not identical"
End If

---

And i think that's it...
sorry i was bored so i decided to explain it in full detail. Hehe i don't even know if you were talking about sizes.

Gl,
D!m

Code:

---

Sub file_compare(file1 As String, file2 As String)
'this checks to files to see if they are identical

Open file1 For Binary As #1
 Open file2 For Binary As #2
 
 issame% = True
 If LOF(1) <> LOF(2) Then
 issame% = False
 Else
 Whole& = LOF(1) \ 10000 'number of whole 10,000 byte chunks
 Part& = LOF(1) Mod 10000 'remaining bytes at end of file
 buffer1$ = String$(10000, 0)
 buffer2$ = String$(10000, 0)
 Start& = 1
 For X& = 1 To Whole& 'this for-next loop will get 10,000
Get #1, Start&, buffer1$ 'byte chunks at a time.
Get #2, Start&, buffer2$

      If buffer1$ <> buffer2$ Then
              issame% = False
              Exit For
      End If

Start& = Start& + 10000
 Next
 buffer1$ = String$(Part&, 0)
 buffer2$ = String$(Part&, 0)
 Get #1, Start&, buffer1$ 'get the remaining bytes at the end
 Get #2, Start&, buffer2$ 'get the remaining bytes at the end
 If buffer1$ <> buffer2$ Then issame% = False
 End If
 
 Close
 If issame% Then
 MsgBox "Files are identical", 64
 Else
 MsgBox "Files are NOT identical", 16
 End If

'Usage:
'Call file_compare("C:\file1.exe", "C:\file\file1.exe")
End Sub

---

[Edited by Matthew Gates on 07-14-2000 at 02:17 AM]

Heh Matthew's tha man. :)

Thanks a lot!

You really helped me!

But is it possible too, not to compare the filesize!

Example:

My Picture is a Tree!

The pic on the webpage is the same Tree but it stands next to a house (both objects on the same picture)

Is it possible to compare the Two trees??

CU

AbsoluteB

It would be easier to detect differences between the images as a whole than it would be for unique objects within the images. For exmaple you could compare the pixel values of both images and keep track of the number of pixels that have the same corresponing color, then inform the user the percentage of color data that the images share. You could then make suggestions based on the percentage like so:

Percentage of matching pixels

100% Same image
90 - 99% Same image minor discrepencies
50 - 89% Similar key objects within the image
0-49% different images with random matching colors

This could lead to a way to compare the trees. Find the smallest bounding box the fits both trees then compare. if you have above 80% similarites you could say that the trees are the same with minor differences.

This routine would be slow for large images though.

Research "Edge Detection".