How Do I Convert A Grayscaled Image To An Array?

Question

0.00/5 (No votes)

See more:

I am not sure but i think gray scaled image is a 1d array. I have already used following code and i don't want to use it again.

Please suggest any thing else.

C#

public byte[] convertToArray(Bitmap grayscaledImage)
        {
            
            MemoryStream m1;
            byte[] imagetoArray;
           
            m1 = new MemoryStream();

            grayscaledImage.Save(m1, System.Drawing.Imaging.ImageFormat.Jpeg); m1.Close();
            imagetoArray = m1.ToArray();
            return imagetoArray;
            
        }

Posted 12-May-14 13:25pm

z3m

Add a Solution

Comments

Sergey Alexandrovich Kryukov 12-May-14 19:44pm

It depends on what you are using. Generally, if you ask about the class Bitmap, you should specify its exact full type name. But...
—SA

z3m 13-May-14 3:10am

Sergey! I am sorry to say but I didn't got your point. :(

Sergey Alexandrovich Kryukov 13-May-14 12:06pm

Please, which part of the expression "exact full type name" (or something else) you did not get?
—SA

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2014-05-12T13:48:00

Solution 1

Please see my comment to the question. But its most likely that you mean System.Drawing.Bitmap and for this class the solution is the use of System.Drawing.Bitmap.LockBits:
http://msdn.microsoft.com/en-us/library/system.drawing.bitmap.lockbits.aspx[^].

Clink on the link on the first of the two methods referenced on the page referenced above; it has a good code sample.

Most important thing here is not to try to use GetPixel in a loop, as this method is prohibitively slow. That's all the whole idea of locking bits in memory is about. Note that you need to learn the memory layout for the PixelFormat you're using. See also: http://msdn.microsoft.com/en-us/library/system.drawing.imaging.pixelformat.aspx[^].

—SA

Posted 12-May-14 13:48pm

Sergey Alexandrovich Kryukov

Comments

CPallini 13-May-14 3:36am

5.

Sergey Alexandrovich Kryukov 13-May-14 12:02pm

Thank you, Carlo.
—SA

z3m 13-May-14 4:24am

I have tried the Bitmap.LockBits method, u can see code down here, but the problem I got is every fourth bit in array is 255 and all thers are 0 like this {0,0,0,255, 0,0,0,255,0,0,0,255}

what could be the reason? please help
"code example is here "
public byte [] returnArray(Bitmap bitmap){
BitmapData bmpData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat);
IntPtr ptr= bmpData.Scan0;
int bytes= Math.Abs(bmpData.Stride)*bmpData.Height;

byte[] rgbvalues= new byte[bytes];

System.Runtime.InteropServices.Marshal.Copy(ptr, rgbvalues, 0, bytes);
return rgbValues;
}

Sergey Alexandrovich Kryukov 13-May-14 12:05pm

Again, check your pixel format. Forth byte must be opacity, and I'm not sure the pixel format is grayscale. It could be ARGB format with actual gray pixels...
—SA