Visual Basic

Comparing images using the GetPixel Method (2)

10-Apr-07 23:10

I'm sure you do. How does VB.NET reflect this, and give people any idea of what you're asking ? Imagine if everyone typed the name of the forum into the header, how hard the forum would be to read.

You can handle the keypress event and either replace the character typed with a capital, or reject it if it isn't a capital.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Re: vb.net

amaneet11-Apr-07 0:12

amaneet

11-Apr-07 0:12

Try the following code on the keypress event
If (e.KeyChar = "A") Then
e.handled=true
else
e.handled=false
End If
hope this may help u.

Zaegra10-Apr-07 23:01

10-Apr-07 23:01

Hello,
I have 2 images, both loaded into pictureboxes. Now, i want to compare them using the GetPixel method (i know i al typed this before Big Grin | :-D

)
I tried the following: (the images have the same size)
but it does not work

Dim btm1 as new bitmap(picturebox1.image)
Dim btm2 as new bitmap(picturebox2.image)
dim i as integer
dim j as integer

for i = 1 to btm1.width
for j = 1 to btm1.height
Dim pixg1 as color
Dim pixg2 as color
pixg1 = btm1.getpixel(i,j)
pixg2 = btm2.getpixel(i,j)
If NOT pixg1 = pixg2 Then
...
End If
next j
next i

Can someone please give me the code to compare 2 images loaded into picturebox by going over each pixel using the GetPixel method it is kind of urgent Big Grin | :-D

Thanks in advance,

--Zaegra--

Christian Graus10-Apr-07 23:09

10-Apr-07 23:09

Zaegra wrote:
know i al typed this before

Yes, over and over. Why not reply to my response ?

Zaegra wrote:
Dim btm1 as new bitmap(picturebox1.image)
Dim btm2 as new bitmap(picturebox2.image)

Wow, that's not convoluted. Why can't it be the same image, instead of a copy ?

Zaegra wrote:
for i = 1 to btm1.width
for j = 1 to btm1.height

They are 0 indexed, and should end at height-1 and width-1 or they will throw an exception. They should also be called x and y for readability.

FWIW, this is also going to be very slow. VB.NET cannot do it faster, but C# can. How big are these images and how often do you need to do this ?

Zaegra11-Apr-07 1:17

11-Apr-07 1:17

well the images are screenshots so the size depends on the resolution of the screen, but their minimum size will be 800x600 and the maximum size 1280x1024. (I am trying to make a program which automatically saves screenshots in an imagelist when the PrintScreen button is pressed but since my program does not respond at key presses if it is not activated i will need a timer which will compare the images and if they don't match, add the screenshot to the imagelist.) Can you help me out please? if you have a different solution, always welcome! (Btw, thanks for helping) Big Grin | :-D

--Zaegra--

Christian Graus11-Apr-07 2:02

11-Apr-07 2:02

OK, by the time your comparison code ends, the screen will have changed.

Read my C# image processing articles for how to access the bits of a bitmap directly. From thre, writing code to compare two bitmaps is trival, and it will be heaps faster. Just write a C# dll that you call from VB.NET.

Zaegra11-Apr-07 2:15

11-Apr-07 2:15

Sorry, i don't use C#, is there no simple way in VB.NET to compare images and: Is there a way to let a window always be on top even in a game which runs in full-screen mode? Because that will solve the problem too.

--Zaegra--

Colin Angus Mackay11-Apr-07 3:02

Colin Angus Mackay

11-Apr-07 3:02

Zaegra wrote:
Sorry, i don't use C#, is there no simple way in VB.NET to compare images

From what I understand, Christian was saying you don't have to use C#. The code to do the comparison happens to be in C#. You can call this from your VB.NET project.

Also, it is a bit finalistic to say "I don't use C#". On a day-to-day basis I don't use VB.NET, but since there are over 45000 similarities between VB.NET and C# and only a few dozen differences it is easy to pick up one if you know the other.

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Dave Kreskowiak11-Apr-07 5:02

Dave Kreskowiak

11-Apr-07 5:02

Zaegra wrote:
is there no simple way in VB.NET to compare images

No, there isn't anything in the .NET Framework pre-written for you to do this.

The code to compare two images has to be written in C# is you want the speed. The reason for this is because C# supports pointers in unsafe code blocks while VB.NET doesn't support pointer at all. You can write the library to do image comparisons in C#, then use the resulting .DLL in your VB.NET project.

Zaegra wrote:
Is there a way to let a window always be on top even in a game which runs in full-screen mode?

If the game uses DirectX, no there isn't. The game isn't rendered in the same frame buffer as the Windows Desktop. Your window WILL be on top of all other windows, but will still not be visible at all under the DirectX render window, if running in full-screen.

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Christian Graus11-Apr-07 10:53

11-Apr-07 10:53

Zaegra wrote:
is there no simple way in VB.NET to compare images

What the other guys said, plus, what you wrote above is the only way in VB.NET, and it's slow.

SQL SERVER

Socheat.Net10-Apr-07 22:43

Socheat.Net

10-Apr-07 22:43

I currently using Visual Studio.Net 2005, I want to create database for SQL but I don't have tool, so please anyone give me address to download it.

................

Re: SQL SERVER

Colin Angus Mackay10-Apr-07 22:49

Colin Angus Mackay

10-Apr-07 22:49

If you put SQL Server 2005 download[^] in to a search engine the first hit will be what you are looking for.

Re: SQL SERVER

_mubashir10-Apr-07 22:49

_mubashir

10-Apr-07 22:49

go and buy a cd for Ms SQL server 2000/2005

Mubashir

Every job is a self portrait of the person who did it.

Re: SQL SERVER

Christian Graus10-Apr-07 22:52

again stumped with arraylists

10-Apr-07 22:52

This means one of two things:

1 - I can't work out how to use google
2 - I'm asking for help in stealing software

If 1, it's pretty simple. If 2, we're not going to help you. SQL Express is free, and easy to find online. SS2005 is not free, and you need to buy it.

Help with reports

Jats_4ru10-Apr-07 22:08

Jats_4ru

10-Apr-07 22:08

Hi,

I am working with a project where there is a need of report generation.

I had developed the report in crystal reports.
All the data is view properly but the only problem is images.

Images i am accepting the data through richtextbox.rtf into the data base and displaying the data back to crystal report using the data object with setting the property o display rtf data.

But it only loads the text data from the database but not the images between the text.

Any help would be great...

Thankx

Jats

Re: Help with reports

Dave Kreskowiak11-Apr-07 4:54

Dave Kreskowiak

11-Apr-07 4:54

You might want to ask this question with BusinessObjects support. I don't know if CrystalReports supports inline images in RTF fields.

[EDIT]
Well, my Google-Fu has failed me but briefly. CrystalReports doesn't support any image tags in RTF data. You can find more on it here[^].

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

srikanthdevsql10-Apr-07 21:58

srikanthdevsql

10-Apr-07 21:58

This is the code:
1.Dim mm As ArrayList = New ArrayList
2.Dim i As Integer
3. For i = 0 To intTotParam - 1
mm.Add(arrInputFileData(arrPosition(i)))
Next
4. Dim ss As String() = mm.Item(0)
5. MessageBox.Show(ss(0))

I am getting the error "Specified cast is not valid" at line 4.
Actually i need to sort the arraylist and find the largest element.
Retrieving the strings that has been added in the arraylists is of primary importance in my project and needed at many places.
Please help me out

Zaegra10-Apr-07 22:04

10-Apr-07 22:04

You can't convert an object to a string just like that.
Try converting it to string format first.

srikanthdevsql10-Apr-07 22:09

srikanthdevsql

10-Apr-07 22:09

can you give me the code
for converting the object to string format
and displaying in message box

Christian Graus10-Apr-07 22:37

Re: to string cannot be used

10-Apr-07 22:37

This is why arraylist totally sucks. You can't use VB.NET 2.0 ?

object has a ToString() method, that's the best way to convert to string.

to string cannot be used

srikanthdevsql10-Apr-07 23:52

srikanthdevsql

10-Apr-07 23:52

I tried the following
Dim ob as object
for each ob in tempArray
dim m as string
m=ob Frown | :(

next
if ob had ToString Method it should have shown...but it only has to
GetType method.
Seems there is no way to retrieve strings from the arraylists Frown | :(

_mubashir11-Apr-07 1:37

_mubashir

11-Apr-07 1:37

Try Cstr(ob)

Mubashir
Software Architect
Storan Technologies Inc, USA
Every job is a self portrait of the person who did it.

Re: to string cannot be used

Christian Graus11-Apr-07 2:00

11-Apr-07 2:00

EVERYTHING in .NET has a ToString() method. It's guarenteed.

srikanth_nair wrote:
Seems there is no way to retrieve strings from the arraylists

Rubbish. If it's a string, you can cast it to string. The issue is, the ArrayList is nasty, it stores objects, ToString would not crash, no matter what the object is.