Introduce ColorMode enum

app/src/main/java/org/fairscan/app/data/ImageRepository.kt

@@ -33,6 +33,7 @@ import org.fairscan.app.domain.PageMetadata
 import org.fairscan.app.domain.PageViewKey
 import org.fairscan.app.domain.Rotation
 import org.fairscan.app.domain.ScanPage
+import org.fairscan.imageprocessing.ColorMode
 import org.fairscan.imageprocessing.Point
 import org.fairscan.imageprocessing.Quad
 import java.io.File
@@ -151,7 +152,7 @@ class ImageRepository(
                     quad = metadata.normalizedQuad.toSerializable(),
                     baseRotationDegrees = metadata.baseRotation.degrees,
                     manualRotationDegrees = Rotation.R0.degrees,
-                    isColored = metadata.isColored
+                    isColored = metadata.autoColorMode == ColorMode.COLOR
                 )
             )
             saveMetadata()
@@ -313,6 +314,6 @@ fun PageV2.toMetadata(): PageMetadata? {
     return PageMetadata(
         quad.toQuad(),
         Rotation.fromDegrees(baseRotationDegrees),
-        isColored
+        if (isColored) ColorMode.COLOR else ColorMode.GRAYSCALE
     )
 }

app/src/main/java/org/fairscan/app/domain/ExportPreparation.kt

@@ -98,7 +98,7 @@ private fun prepareJpegForHigh(
             decoded,
             quad,
             pageMetadata.baseRotation.add(manualRotation).degrees,
-            pageMetadata.isColored,
+            pageMetadata.autoColorMode,
             exportQuality.maxPixels
         )
         return Jpeg.fromMat(page, exportQuality.jpegQuality)

app/src/main/java/org/fairscan/app/domain/Page.kt

@@ -14,12 +14,13 @@
  */
 package org.fairscan.app.domain
 
+import org.fairscan.imageprocessing.ColorMode
 import org.fairscan.imageprocessing.Quad
 
 data class PageMetadata(
     val normalizedQuad: Quad,
     val baseRotation: Rotation,
-    val isColored: Boolean,
+    val autoColorMode: ColorMode,
 )
 
 data class ScanPage(

app/src/main/java/org/fairscan/app/ui/screens/camera/CameraScreen.kt

@@ -104,6 +104,7 @@ import org.fairscan.app.ui.components.pageCountText
 import org.fairscan.app.ui.dummyNavigation
 import org.fairscan.app.ui.fakeDocument
 import org.fairscan.app.ui.theme.FairScanTheme
+import org.fairscan.imageprocessing.ColorMode
 import org.fairscan.imageprocessing.Point
 import org.fairscan.imageprocessing.Quad
 
@@ -539,7 +540,7 @@ fun CameraScreenPreviewWithProcessedImage() {
         CapturedPage(
             debugImage("gallica.bnf.fr-bpt6k5530456s-1.jpg"),
             CompletableDeferred(Jpeg(ByteArray(0))),
-            PageMetadata(quad, R0, false))))
+            PageMetadata(quad, R0, ColorMode.COLOR))))
 }
 
 @Preview(showBackground = true, widthDp = 640, heightDp = 320)

app/src/main/java/org/fairscan/app/ui/screens/camera/CameraViewModel.kt

@@ -40,7 +40,7 @@ import org.fairscan.imageprocessing.Mask
 import org.fairscan.imageprocessing.Quad
 import org.fairscan.imageprocessing.detectDocumentQuad
 import org.fairscan.imageprocessing.extractDocument
-import org.fairscan.imageprocessing.isColoredDocument
+import org.fairscan.imageprocessing.autoColorMode
 import org.fairscan.imageprocessing.scaledTo
 import org.opencv.android.Utils
 import org.opencv.core.Mat
@@ -230,16 +230,16 @@ fun extractDocumentFromBitmap(
     val bgr = Mat()
     Imgproc.cvtColor(rgba, bgr, Imgproc.COLOR_RGBA2BGR) // CV_8UC4 → CV_8UC3
     rgba.release()
-    val isColored = isColoredDocument(bgr, mask, quad)
+    val colorMode = autoColorMode(bgr, mask, quad)
     val maxPixels = ExportQuality.BALANCED.maxPixels
-    val page = extractDocument(bgr, quad, rotationDegrees, isColored, maxPixels)
+    val page = extractDocument(bgr, quad, rotationDegrees, colorMode, maxPixels)
     val pageJpeg = Jpeg.fromMat(page, ExportQuality.BALANCED.jpegQuality)
     bgr.release()
     page.release()
 
     val normalizedQuad = quad.scaledTo(source.width, source.height, 1, 1)
     val baseRotation = Rotation.fromDegrees(rotationDegrees)
-    val metadata = PageMetadata(normalizedQuad, baseRotation, isColored)
+    val metadata = PageMetadata(normalizedQuad, baseRotation, colorMode)
     val sourceJpegDeferred = viewModelScope.async(Dispatchers.IO) {
         compressJpeg(source, 90)
     }