Reputation: 449
I am new in working with Bitmap and using 16 bits per pixel Format16bppRgb555
;
I want to Extract RGB Values from Bitmap Data. Here is my code
static void Main(string[] args)
{
BitmapRGBValues();
Console.ReadKey();
}
static unsafe void BitmapRGBValues()
{
Bitmap cur = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format16bppRgb555);
//Capture Screen
var screenBounds = Screen.PrimaryScreen.Bounds;
using (var gfxScreenshot = Graphics.FromImage(cur))
{
gfxScreenshot.CopyFromScreen(screenBounds.X, screenBounds.Y, 0, 0, screenBounds.Size, CopyPixelOperation.SourceCopy);
}
var curBitmapData = cur.LockBits(new Rectangle(0, 0, cur.Width, cur.Height),
ImageLockMode.ReadWrite, PixelFormat.Format16bppRgb555);
try
{
byte* scan0 = (byte*)curBitmapData.Scan0.ToPointer();
for (int y = 0; y < cur.Height; ++y)
{
ulong* curRow = (ulong*)(scan0 + curBitmapData.Stride * y);
for (int x = 0; x < curBitmapData.Stride / 8; ++x)
{
ulong pixel = curRow[x];
//How to get RGB Values from pixel;
}
}
}
catch
{
}
finally
{
cur.UnlockBits(curBitmapData);
}
}
Upvotes: 3
Views: 5190
Reputation: 5639
LockBits can actually convert your image to a desired pixel format, meaning no further conversion should be needed. Just lock the image as Format32bppArgb
and you can simply take your colour values from single bytes.
BitmapData curBitmapData = cur.LockBits(new Rectangle(0, 0, cur.Width, cur.Height),
ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
Int32 stride = curBitmapData.Stride;
Byte[] data = new Byte[stride * cur.Height];
Marshal.Copy(curBitmapData.Scan0, data, 0, data.Length);
cur.UnlockBits(curBitmapData);
With this code, you end up with the byte array data
, which is filled with your image data in ARGB format, meaning the colour component bytes will be in there in the order [B, G, R, A]. Note that the stride
is the amount of bytes to skip to get to a next line on the image, and since this is not always equal to "width * bytes per pixel", it should always be taken into account.
Now you got that, you can do whatever you want with it...
Int32 curRowOffs = 0;
for (Int32 y = 0; y < cur.Height; y++)
{
// Set offset to start of current row
Int32 curOffs = curRowOffs;
for (Int32 x = 0; x < cur.Width; x++)
{
// ARGB = bytes [B,G,R,A]
Byte b = data[curOffs];
Byte g = data[curOffs + 1];
Byte r = data[curOffs + 2];
Byte a = data[curOffs + 3];
Color col = Color.FromArgb(a, r, g, b);
// Do whatever you want with your colour here
// ...
// Increase offset to next colour
curOffs += 4;
}
// Increase row offset
curRowOffs += stride;
}
You can even edit the bytes, and then build a new image from them if you want.
Upvotes: 7