Solved

How to traverse pixels in Monochrome Bitmap (pf1bit)

Posted on 1999-01-14
4
1,277 Views
Last Modified: 2008-03-17
Sir,
     Basically I want to traverse each pixel in a monochrome bitmap. I tried using PByteArray (for Scanline..) and to loop through the bitmap I've also given Bitmap.Width - 8.
But this method is not working. In Short I want to traverse each pixel, get color info for that pixel and do some calculations based on it,
Please Help me out.
Regards, Jagan
0
Comment
Question by:rjagan
4 Comments
 
LVL 20

Expert Comment

by:Madshi
ID: 1356560
Hi Jagan,

you can either use the ScanLine property. Perhaps the following example from the delphi help file will help you with that...

The problem with this ScanLine property is that you have to bother with things like color depth.
So the example below works only with 256 color bitmaps.

procedure TForm1.Button1Click(Sender: TObject);

// Zeichnung direkt in das BitMap-Objekt ausgeben
var
  x,y : integer;
  BitMap : TBitMap;
  P : PByteArray;
begin
  BitMap := TBitMap.create;
  try
    BitMap.LoadFromFile('..\Images\Splash\256color\factory.bmp');
    for y := 0 to BitMap.height -1 do
    begin
      P := BitMap.ScanLine[y];
      for x := 0 to BitMap.width -1 do
        P[x] := y;
    end;
  canvas.draw(0,0,BitMap);
  finally
    BitMap.free;
  end;
end;

Or you could use the bitmap.canvas.pixels property, which is easier to use, but much much slower...

Regards, Madshi.
0
 

Accepted Solution

by:
DOsinga earned 30 total points
ID: 1356561
You might also have a try with the WinApi GetDIBits functions. This will allow you to copy the pixels of the bitmap in a format of your choice, to be specified in a passed TBitmapInfo.
0
 
LVL 10

Expert Comment

by:viktornet
ID: 1356562
YOu go pixel by pixel through the bitmap in order to get eac pixel and do some calculations top it...


for y := 0 to Bitmap.Height do
  for x := 0 to Bitmap.Width do
    bitmap.canvas.pixels[x, y] := bitmap.canvas.pixels[x, y] xor $fafafafa;

-Viktor
--Ivanov
0
 

Author Comment

by:rjagan
ID: 1356563
Thanks a lot for your consideration
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Objective: - This article will help user in how to convert their numeric value become words. How to use 1. You can copy this code in your Unit as function 2. than you can perform your function by type this code The Code   (CODE) The Im…
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

809 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question