Get all pixel information of an image efficiently

Question

I made a program to get all image pixel RGB color codes from picture. Basically, it sets y position on constant and changes x position zero to width and also y by looping. <

Answer 1

Getting pixel information shouldn't take that long. Can you log the time it takes myimage() to run? The slowness might be somewhere else. Also try removing the line that begins with textBox2.AppendText in myimage() and see how fast it runs then.

Answer 2

Take a look at this:

var data = mypic.LockBits(
    new Rectangle(Point.Empty, mypic.Size),
    ImageLockMode.ReadWrite, mypic.PixelFormat);
var pixelSize = data.PixelFormat == PixelFormat.Format32bppArgb ? 4 : 3; // only works with 32 or 24 pixel-size bitmap!
var padding = data.Stride - (data.Width * pixelSize);
var bytes = new byte[data.Height * data.Stride];

// copy the bytes from bitmap to array
Marshal.Copy(data.Scan0, bytes, 0, bytes.Length);

var index = 0;
var builder = new StringBuilder();

for (var y = 0; y < data.Height; y++)
{
    for (var x = 0; x < data.Width; x++)
    {
        Color pixelColor = Color.FromArgb(
            pixelSize == 3 ? 255 : bytes[index + 3], // A component if present
            bytes[index + 2], // R component
            bytes[index + 1], // G component
            bytes[index]      // B component
            );

        builder
            .Append("  ")
            .Append(pixelColor.R)
            .Append("     ")
            .Append(pixelColor.G)
            .Append("     ")
            .Append(pixelColor.B)
            .Append("     ")
            .Append(pixelColor.A)
            .AppendLine();

        index += pixelSize;
    }

    index += padding;
}

// copy back the bytes from array to the bitmap
Marshal.Copy(bytes, 0, data.Scan0, bytes.Length);

textBox2.Text = builder.ToString();

Is just an example, read some good tutorials about LockBits and imaging in general to understand clearly what happens.