AiQ_GUI/Camera/ImageProcessing.cs

using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;
using System.Drawing.Imaging;
using System.Net;
using Image = System.Drawing.Image;

namespace AiQ_GUI
{
    internal class ImageProcessing
    {
        // API to get snapshot then downsize and downscale image to save size.
        public static async Task<Image?> GetProcessedImage(string suffix, string IPAddress, string DevPass, string? savePath = null, PictureBox? PcBx = null, bool SaveDisplay = false)
        {
            try
            {
                string requestUrl = $"http://{IPAddress}/{suffix}";

                HttpClientHandler handler = new HttpClientHandler
                {
                    Credentials = new NetworkCredential("developer", DevPass),
                    PreAuthenticate = true
                };

                using HttpClient httpClient = new(handler);
                HttpResponseMessage response = await httpClient.GetAsync(requestUrl);
                if (!response.IsSuccessStatusCode)
                {
                    MainForm.Instance.AddToActionsList($"No success from {requestUrl} replied {response.StatusCode}");
                    return null;
                }

                byte[] imageBytes = await response.Content.ReadAsByteArrayAsync();

                if (imageBytes.Length == 0) // Check if the imageBytes is empty
                {
                    MainForm.Instance.AddToActionsList($"No image data received from {requestUrl}");
                    return null;
                }

                // Load image into Emgu CV Mat
                Mat mat = new();
                CvInvoke.Imdecode(imageBytes, ImreadModes.AnyColor, mat);
                if (mat.IsEmpty)
                {
                    MainForm.Instance.AddToActionsList("Failed to decode image with Emgu CV.");
                    return null;
                }

                // Downscale image to 25% resolution of 1080p
                Mat downscaledMat = new();
                CvInvoke.Resize(mat, downscaledMat, new Size(480, 270));

                // Compress to JPEG at 75% quality
                byte[] jpegBytes = downscaledMat.ToImage<Bgr, byte>().ToJpegData(75);

                // Convert back to System.Drawing.Image
                using MemoryStream ms = new(jpegBytes);
                Image IMG = Image.FromStream(ms);

                // Display image in picture box
                if (SaveDisplay && PcBx != null)
                    PcBx.Image = (Image)IMG.Clone();

                // Save image to disk
                if (SaveDisplay && !string.IsNullOrEmpty(savePath))
                    IMG.Save(savePath, ImageFormat.Jpeg);

                return IMG;
            }
            catch (HttpRequestException ex)
            {
                MainForm.Instance.AddToActionsList($"HTTP error: {ex.Message}");
                return null;
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error processing image: {ex.Message}");
                return null;
            }
        }

        // Checks the images taken at different iris settings and compares their brightness.
        // Also gets the colour snapshot
        public static async Task ImageCheck(PictureBox PicBxOV, PictureBox PicBxF2, PictureBox PicBxF16, Label LblF2, Label LblF16, Camera CamOnTest)
        {
            // Take OV snapshot 
            Task<Image?> Colour_Response = GetProcessedImage("Colour-snapshot", CamOnTest.IP, CamOnTest.DevPass, LDS.MAVPath + LDS.OVsavePath, PicBxOV, true);

            // Change to wide iris F2.0
            await FlexiAPI.APIHTTPVISCA(CamOnTest.IP, "8101044B00000100FF", true);

            await Task.Delay(200); // Wait for iris to settle before taking IR image

            // Take IR bright light image
            Image? F2_Response = await GetProcessedImage("Infrared-snapshot", CamOnTest.IP, CamOnTest.DevPass, LDS.MAVPath + LDS.IROpensavePath, PicBxF2, true);
            if (F2_Response == null)
            {
                MainForm.Instance.AddToActionsList("IR F2.0 image response is blank.");
                return;
            }

            // Change to tight iris F16.0
            await FlexiAPI.APIHTTPVISCA(CamOnTest.IP, "8101044B00000004FF", true);

            await Task.Delay(200); // Wait for iris to settle before taking IR image

            // Take IR low light image
            Image? F16_Response = await GetProcessedImage("Infrared-snapshot", CamOnTest.IP, CamOnTest.DevPass, LDS.MAVPath + LDS.IRTightsavePath, PicBxF16, true);
            if (F16_Response == null)
            {
                MainForm.Instance.AddToActionsList("IR F16.0 image response is blank.");
                return;
            }

            try
            {
                if (await Colour_Response == null)
                {
                    MainForm.Instance.AddToActionsList("Colour image response is blank.");
                    return;
                }
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error awaiting Colour snapshot: {ex.Message}");
                return;
            }

            // Brightness test between min and max iris
            try
            {
                double luminanceF2 = GetMeanLuminance(F2_Response);
                double luminanceF16 = GetMeanLuminance(F16_Response);

                LblF2.Text += luminanceF2 + "%";
                LblF16.Text += luminanceF16 + "%";

                if (luminanceF2 < luminanceF16 * 1.01)
                {
                    MainForm.Instance.AddToActionsList("Insufficient luminance contrast between min and max iris");
                    LblF2.ForeColor = LblF16.ForeColor = Color.Red;
                }
                else
                    LblF2.ForeColor = LblF16.ForeColor = Color.LightGreen;
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error calculating luminance: {ex.Message}");
                return;
            }
        }

        public static double GetMeanLuminance(Image Img)
        {
            using Bitmap bmp = new(Img); // Convert from Image to Bitmap

            using MemoryStream ms = new(); // Convert Bitmap to byte array
            bmp.Save(ms, ImageFormat.Jpeg);
            byte[] bmpBytes = ms.ToArray();

            Mat mat = new();
            CvInvoke.Imdecode(bmpBytes, ImreadModes.AnyColor, mat); // Convert to mat

            Mat grayMat = new();
            CvInvoke.CvtColor(mat, grayMat, ColorConversion.Bgr2Gray); // Convert to grayscale

            MCvScalar mean = CvInvoke.Mean(grayMat); // Calculate mean luminance
            // Translate to a percentage from a mean value between 0-255 8 bit grayscale value
            return Math.Round((mean.V0 / 255) * 100, 4); // V0 contains the mean value for grayscale
        }
    }
}