CODEWITHSUNDEEP
c#
Umair Asher
Umair Asher

Reputation: 35

How to get pixels of ONLY last ROW of an image and display it in picture box. C#

I have a question that how can we get pixels of only last row of an image and display that row in a picturebox of C# application.

Upvotes: 1

Views: 203

Answers (3)

Ivan Stoev
Ivan Stoev

Reputation: 205779

The easiest (but also fastest) way I see is to use the following Bitmap Constructor (Int32, Int32, Int32, PixelFormat, IntPtr) overload in combination with Bitmap.LockBits / Bitmap.UnlockBits like this

static Bitmap GetLastRow(Bitmap source)
{
    var data = source.LockBits(new Rectangle(0, source.Height - 1, source.Width, 1), ImageLockMode.ReadOnly, source.PixelFormat);
    try { return new Bitmap(data.Width, data.Height, data.Stride, data.PixelFormat, data.Scan0); }
    finally { source.UnlockBits(data); }
}

In general you can use this code to crop any rectangular part of a bitmap by just changing the new Rectangle(...) part.

Update: It turns out that there is even a predefined method - Bitmap.Clone(Rectangle, PixelFormat), so the code could be simply

Bitmap source = ...;
var lastRow = source.Clone(new Rectangle(0, source.Height - 1, source.Width, 1), source.PixelFormat);

Upvotes: 2

cramopy
cramopy

Reputation: 3497

public Bitmap LastRow(Bitmap source)
{
   int y = source.Height - 1;
   Bitmap newSource = new Bitmap(source.Width, 1);
   for (int x = 0; x < source.Width; x++)
   {
       NewSource.SetPixel(x, y, Source.GetPixel(x, y));
   }
   return newSource;
}

Sample usage:

pictureBox1.Image = LastRow(yourImage);

Upvotes: 1

Tam&#225;s F
Tam&#225;s F

Reputation: 168

Probably not the fastest way, but should work:

        Bitmap image1 = new Bitmap(@"picture.bmp");
        Bitmap image2 = new Bitmap(image1.Width, 1, image1.PixelFormat);
        for (int i = 0; i < image1.Width; i++)
        {
            image2.SetPixel(i, 0, image1.GetPixel(i, image1.Height - 1));
        }
        pictureBox1.Image = image2;

Upvotes: 0

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