Add viewing thermal reference images

Author: olaals

api/.env.example

@@ -1,6 +1,3 @@
-# Storage
-Storage__ThermalReferenceStorageAccount=saradevthermalref
-
 # PostgreSQL server name (without .postgres.database.azure.com suffix)
 Database__Server=robotics-dev-psql-server
 
@@ -12,4 +9,3 @@ Database__User=sara-dev
 
 # Thermal reference storage account
 Storage__ThermalReferenceStorageAccount=saradevthermalref
-

api/Controllers/ThermalReferenceMetadataController.cs

@@ -11,6 +11,7 @@ namespace api.Controllers;
 public class ThermalReferenceMetadataController(
     ILogger<ThermalReferenceMetadataController> logger,
     IThermalReferenceMetadataService thermalReferenceMetadataService,
+    IThermalImageService thermalImageService,
     IConfiguration configuration
 ) : ControllerBase
 {
@@ -164,6 +165,49 @@ public async Task<ActionResult> DeleteThermalReferenceMetadata([FromRoute] Guid
         }
     }
 
+    [HttpGet("id/{id}/image")]
+    [Authorize(Roles = Role.Any)]
+    [ProducesResponseType(typeof(FileContentResult), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult> GetThermalReferenceImage([FromRoute] Guid id)
+    {
+        try
+        {
+            var metadata = await thermalReferenceMetadataService.ReadById(id);
+            if (metadata is null)
+            {
+                return NotFound($"Could not find thermal reference metadata with id {id}");
+            }
+
+            var result = await thermalImageService.GetThermalImageDataAsync(
+                metadata.ReferenceImageBlobStorageLocation
+            );
+
+            Response.Headers["X-Image-Width"] = result.Width.ToString();
+            Response.Headers["X-Image-Height"] = result.Height.ToString();
+            Response.Headers["X-Temperature-Min"] = result.MinTemperature.ToString(
+                "G9",
+                System.Globalization.CultureInfo.InvariantCulture
+            );
+            Response.Headers["X-Temperature-Max"] = result.MaxTemperature.ToString(
+                "G9",
+                System.Globalization.CultureInfo.InvariantCulture
+            );
+            Response.Headers["Access-Control-Expose-Headers"] =
+                "X-Image-Width, X-Image-Height, X-Temperature-Min, X-Temperature-Max";
+
+            return File(result.FloatBytes, "application/octet-stream");
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Error generating thermal reference image for id {Id}", id);
+            return StatusCode(
+                StatusCodes.Status500InternalServerError,
+                "An error occurred while generating the thermal reference image"
+            );
+        }
+    }
+
     private (
         BlobStorageLocation imageLocation,
         BlobStorageLocation polygonLocation

api/Program.cs

@@ -69,6 +69,8 @@
 );
 
 builder.Services.AddScoped<IThermalReferenceMetadataService, ThermalReferenceMetadataService>();
+builder.Services.AddScoped<IBlobStorageService, BlobStorageService>();
+builder.Services.AddScoped<IThermalImageService, ThermalImageService>();
 builder.Services.AddScoped<IInspectionRecordService, InspectionRecordService>();
 builder.Services.AddScoped<IAnalysisService, AnalysisService>();
 builder.Services.AddScoped<IAnalysisGroupService, AnalysisGroupService>();

api/Services/BlobStorageService.cs

@@ -0,0 +1,42 @@
+using api.Database.Models;
+using Azure.Core;
+using Azure.Storage.Blobs;
+
+namespace api.Services;
+
+public interface IBlobStorageService
+{
+    Task<MemoryStream> DownloadBlobAsync(BlobStorageLocation location);
+}
+
+public class BlobStorageService(TokenCredential credential) : IBlobStorageService
+{
+    public async Task<MemoryStream> DownloadBlobAsync(BlobStorageLocation location)
+    {
+        if (string.IsNullOrWhiteSpace(location.StorageAccount))
+            throw new InvalidOperationException("BlobStorageLocation.StorageAccount is empty.");
+
+        if (string.IsNullOrWhiteSpace(location.BlobContainer))
+            throw new InvalidOperationException(
+                $"BlobStorageLocation.BlobContainer is empty for storage account '{location.StorageAccount}'."
+            );
+
+        if (string.IsNullOrWhiteSpace(location.BlobName))
+            throw new InvalidOperationException(
+                $"BlobStorageLocation.BlobName is empty for storage account '{location.StorageAccount}/{location.BlobContainer}'."
+            );
+
+        var serviceClient = new BlobServiceClient(
+            new Uri($"https://{location.StorageAccount}.blob.core.windows.net"),
+            credential
+        );
+
+        var containerClient = serviceClient.GetBlobContainerClient(location.BlobContainer);
+        var blobClient = containerClient.GetBlobClient(location.BlobName);
+
+        var stream = new MemoryStream();
+        await blobClient.DownloadToAsync(stream);
+        stream.Position = 0;
+        return stream;
+    }
+}

api/Services/ThermalImageService.cs

@@ -0,0 +1,102 @@
+using System.Runtime.InteropServices;
+using api.Database.Models;
+using BitMiracle.LibTiff.Classic;
+
+namespace api.Services;
+
+public record ThermalImageData(
+    byte[] FloatBytes,
+    int Width,
+    int Height,
+    float MinTemperature,
+    float MaxTemperature
+);
+
+public interface IThermalImageService
+{
+    Task<ThermalImageData> GetThermalImageDataAsync(BlobStorageLocation location);
+}
+
+public class ThermalImageService(IBlobStorageService blobStorageService) : IThermalImageService
+{
+    public async Task<ThermalImageData> GetThermalImageDataAsync(BlobStorageLocation location)
+    {
+        using var tiffStream = await blobStorageService.DownloadBlobAsync(location);
+
+        var (temperatures, width, height) = ReadTiffTemperatures(tiffStream);
+
+        float minTemp = float.MaxValue;
+        float maxTemp = float.MinValue;
+        for (int i = 0; i < temperatures.Length; i++)
+        {
+            float temp = temperatures[i];
+            if (temp < minTemp)
+                minTemp = temp;
+            if (temp > maxTemp)
+                maxTemp = temp;
+        }
+
+        // Serialize float[] to little-endian bytes.
+        var floatBytes = new byte[temperatures.Length * sizeof(float)];
+        MemoryMarshal.AsBytes(temperatures.AsSpan()).CopyTo(floatBytes);
+
+        return new ThermalImageData(floatBytes, width, height, minTemp, maxTemp);
+    }
+
+    /// <summary>
+    /// Read pixel data from a TIFF stream as float temperatures.
+    /// Supports 32-bit float, 64-bit float, 16-bit unsigned, and 8-bit unsigned sample formats.
+    /// </summary>
+    private static (float[] temperatures, int width, int height) ReadTiffTemperatures(
+        Stream tiffStream
+    )
+    {
+        using var tiff = Tiff.ClientOpen("thermal", "r", tiffStream, new TiffStream());
+        if (tiff == null)
+            throw new InvalidOperationException("Failed to open TIFF stream.");
+
+        int width = tiff.GetField(TiffTag.IMAGEWIDTH)[0].ToInt();
+        int height = tiff.GetField(TiffTag.IMAGELENGTH)[0].ToInt();
+
+        int bitsPerSample = 32;
+        var bpsField = tiff.GetField(TiffTag.BITSPERSAMPLE);
+        if (bpsField != null)
+            bitsPerSample = bpsField[0].ToInt();
+
+        int sampleFormat = (int)SampleFormat.UINT;
+        var sfField = tiff.GetField(TiffTag.SAMPLEFORMAT);
+        if (sfField != null)
+            sampleFormat = sfField[0].ToInt();
+
+        var temperatures = new float[width * height];
+        int scanlineSize = tiff.ScanlineSize();
+        byte[] buffer = new byte[scanlineSize];
+
+        for (int y = 0; y < height; y++)
+        {
+            tiff.ReadScanline(buffer, y);
+
+            for (int x = 0; x < width; x++)
+            {
+                float value = (bitsPerSample, sampleFormat) switch
+                {
+                    (32, (int)SampleFormat.IEEEFP) => BitConverter.ToSingle(buffer, x * 4),
+                    (64, (int)SampleFormat.IEEEFP) => (float)BitConverter.ToDouble(buffer, x * 8),
+                    (16, (int)SampleFormat.UINT or (int)SampleFormat.VOID) => BitConverter.ToUInt16(
+                        buffer,
+                        x * 2
+                    ),
+                    (16, (int)SampleFormat.INT) => BitConverter.ToInt16(buffer, x * 2),
+                    (8, _) => buffer[x],
+                    _ => throw new NotSupportedException(
+                        $"Unsupported TIFF pixel format: {bitsPerSample} bits/sample, sample format {sampleFormat}."
+                    ),
+                };
+
+                temperatures[y * width + x] = value;
+            }
+        }
+
+        return (temperatures, width, height);
+    }
+}

api/api.csproj

@@ -16,6 +16,7 @@
 
   <ItemGroup>
     <PackageReference Include="Azure.Storage.Blobs" Version="12.27.0" />
+    <PackageReference Include="BitMiracle.LibTiff.NET" Version="2.4.660" />
     <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="3.1.0" />
     <PackageReference Include="Microsoft.Data.Sqlite" Version="10.0.7" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="10.0.7" />

frontend/package.json

@@ -14,8 +14,12 @@
     "@equinor/eds-core-react": "^2.5.0",
     "@equinor/eds-icons": "^1.4.0",
     "@equinor/eds-tokens": "^2.2.0",
+    "@types/d3-scale-chromatic": "^3.1.0",
+    "d3-scale-chromatic": "^3.1.0",
+    "konva": "^10.3.0",
     "react": "^19.2.5",
     "react-dom": "^19.2.5",
+    "react-konva": "^19.2.4",
     "react-router": "^7.14.0",
     "styled-components": "^6.4.0"
   },