lockbits

EDIT: I deeply appreciate the replies. What I need more than anything here is sample code for what I do with the few lines of code in the nested loop, since that's what works right in GetPixel/SetPixel, but also what I can't get to work right using Lockbits. Thank you I'm trying to convert my image processing filters from GetPixel / SetPixel to Lockbits, to improve processing time. I have seen Lockbits tutorials here on Stack Overflow, MSDN, and other sites as well, but I'm doing something wrong. I'm starting with an exceedingly simple filter, which simply reduces green to create a red and

I am using the below code to extract RGB values from images, sometimes this works, however on certain files (seemingly where the Stride is not divisible by the width of the bitmap) it is returning mixed up values: Dim rect As New Rectangle(0, 0, bmp.Width, bmp.Height) Dim bmpData As System.Drawing.Imaging.BitmapData = bmp.LockBits(rect, Imaging.ImageLockMode.ReadOnly, Imaging.PixelFormat.Format24bppRgb) Dim ptr As IntPtr = bmpData.Scan0 Dim cols As New List(Of Color) Dim bytes As Integer = Math.Abs(bmpData.Stride) * bmp.Height Dim rgbValues(bytes - 1) As Byte System.Runtime.InteropServices

So, I am very confused over a quick test that I just ran. I am doing some image processing in C#. Get/SetPixel() have proven to be too slow, so I am using LockBits to get at the raw data. However, I seem to have hit a situation which I can't figure out. While scanning the image, it seems that each pixel is laid out as Bgra, that is, blue byte, green byte, red byte, and alpha, in that order. I was under the impression that they would be laid out in Argb order. here is a sample of the code that I am using. BitmapData baseData = m_baseImage.LockBits(new Rectangle(new Point(0, 0), m_baseImage.Size

I was wondering if there's a way in order to remove the padding generated by the 24 bit Bitmap for each scan line. What I mean is like this : Original [Pure Cyan 24 Bit BMP] : FF FF 00 FF FF 00 FF FF **00 00** FF FF 00 FF FF 00 FF FF 00 Desired output [Removed Padding] : FF FF 00 FF FF 00 FF FF **00** FF FF 00 FF FF 00 FF FF 00 Here's my code for getting the pixel data. Bitmap tmp_bitmap = BitmapFromFile; Rectangle rect = new Rectangle(0, 0, tmp_bitmap.Width, tmp_bitmap.Height); System.Drawing.Imaging.BitmapData bmpData = tmp_bitmap.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite

Is that ok to Write and Read directly from a unlocked Bitmap unmanaged memory? Can I keep using the BitmapData after I UnlockBits of the Bitmap? I did a test app where I can read the pixel of the Bitmap of a PictureBox at mouse position while another thread is writing pixels to the same Bitmap. EDIT 1: As Boing have pointed out in his answer: "Scan0 does not point to the actual pixel data of the Bitmap object; rather, it points to a temporary buffer that represents a portion of the pixel data in the Bitmap object." from MSDN . But once I get the Scan0, I'm able to read/write to the Bitmap