Image captured is incorrect

oldgrannyy

Hi, i tried to get the image from the camera but the image is incorrect.

I'm using ZWO ASI290MM.

cbStat = false;


            zwoCam.StopVideoCapture();
            zwoCam.StartExposure(50, false);
            expPtr = Marshal.AllocHGlobal(bufferSize);
            zwoCam.GetExposureData(expPtr, bufferSize);
            expBuffer = new Byte;
            Marshal.Copy(expPtr, expBuffer, 0, bufferSize);
            Marshal.FreeHGlobal(expPtr);
            int col = imageSize.Width;
            int row = imageSize.Height;
            int stride = col;
            Bitmap im = new Bitmap(col, row, stride, System.Drawing.Imaging.PixelFormat.Format8bppIndexed, Marshal.UnsafeAddrOfPinnedArrayElement(expBuffer, 0));
            String dir = "D:\\captures\\" + String.Format("{0-hh-mm-ss-fff-tt}", DateTime.Now) + ".png";
            //save image to directory

im.Save(dir, System.Drawing.Imaging.ImageFormat.Png);

I also tried the GetVideoData and the image isn't correct.

03Jun-02-13-17-977-PM.png

I used Format8ppIndexed for this.

Bitmap im = new Bitmap(col, row, stride, System.Drawing.Imaging.PixelFormat.Format8bppIndexed,

Marshal.UnsafeAddrOfPinnedArrayElement(buffer, 0));

03Jun-02-23-17-809-PM.png

I used Format1bppIndexed for this.

Its supposed to be a smooth white image according to SharpCap.

Please advice, thanks.

yang

if you use Format8bppIndexed, the image does not look like that in SharpCap, you can try to use other image format.

besides, in the second image you attached, I can see vertical line, but not with the first image, what is the difference when capturing these two images in setup?

oldgrannyy

Hi,

thanks for the reply. The second image attached uses Format1bppIndexed while the first image attached uses Format8bppIndexed. I'll try again and let you know if the problem persist.

Thanks!

yang

If you want to display captured data as normal color, you should use Format24bppRgb, and fill R G B bytes with correct value for each pixel, for RAW8, fill R G B with the same value

oldgrannyy

So for a RAW8, I used this:

Bitmap im = new Bitmap(col, row, stride, PixelFormat.Format24bppRgb, Marshal.UnsafeAddrOfPinnedArrayElement(lvBuffer, 0));

Correct?

yang

int IMAGE_WIDTH = SelectedCameraInThr.CaptureAreaInfo.Size.Width;

int IMAGE_HEIGHT = SelectedCameraInThr.CaptureAreaInfo.Size.Height;

int stride = IMAGE_WIDTH;

Bitmap b24bpp = new Bitmap(IMAGE_WIDTH, IMAGE_HEIGHT, PixelFormat.Format24bppRgb);

var rect = new Rectangle(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT);

var bitmapBytes = new byte;

var bmp = new Bitmap(pictureBox.Width, pictureBox.Height, PixelFormat.Format24bppRgb);

var graph = Graphics.FromImage(bmp);

float scale = (float)Math.Min(1.0 * pictureBox.Width / IMAGE_WIDTH, 1.0 * pictureBox.Height / IMAGE_HEIGHT);

var scaleWidth = (int)(IMAGE_WIDTH * scale);

var scaleHeight = (int)(IMAGE_HEIGHT * scale);

Rectangle PicRect = new Rectangle((pictureBox.Width - scaleWidth) / 2, (pictureBox.Height - scaleHeight) / 2, scaleWidth, scaleHeight);

while (bCapture )

{

exp = CamCtrl.Value/1000;

exp = exp > 200 ? 200 : exp;

if (SelectedCameraInThr.GetVideoData(dataPtr, bufferSize, exp))

{

Marshal.Copy(dataPtr, buffer, 0, bufferSize);

var bitmapData = b24bpp.LockBits(rect, ImageLockMode.WriteOnly, b24bpp.PixelFormat);

var numberOfBytes = bitmapData.Stride * IMAGE_HEIGHT;

var ptr = bitmapData.Scan0;

if(SelectedCameraInThr.CaptureAreaInfo.ImageType == ASICameraDll.ASI_IMG_TYPE.ASI_IMG_RAW8

|| SelectedCameraInThr.CaptureAreaInfo.ImageType == ASICameraDll.ASI_IMG_TYPE.ASI_IMG_Y8)

{

int j = 0;

foreach (byte i in buffer)

{

bitmapBytes = i;

}

Marshal.Copy(bitmapBytes, 0, ptr, bitmapBytes.Length);

}

else if (SelectedCameraInThr.CaptureAreaInfo.ImageType == ASICameraDll.ASI_IMG_TYPE.ASI_IMG_RGB24)

{

Marshal.Copy(buffer, 0, ptr, bitmapBytes.Length);

}

else

{

int i, j = 0, iLen = buffer.GetLength(0);

byte Temp8;

for (i = 1; i < iLen; i += 2)

{

Temp8 = buffer;

bitmapBytes = Temp8;

bitmapBytes = Temp8;

bitmapBytes = Temp8;

}

Marshal.Copy(bitmapBytes, 0, ptr, bitmapBytes.Length);

}

b24bpp.UnlockBits(bitmapData);

graph.DrawImage(b24bpp, PicRect);

pictureBox.Image = bmp;

}

}