refactor: Crop nach Deskew/Dewarp verschieben + content-basierter Buchscan-Crop

Pipeline-Reihenfolge neu: Orientierung → Begradigung → Entzerrung → Zuschneiden → Spalten...
Crop arbeitet jetzt auf dem bereits geraden Bild, was bessere Ergebnisse liefert.

page_crop.py komplett ersetzt: Adaptive Threshold + 4-Kanten-Erkennung
(Buchruecken-Schatten links, Ink-Projektion fuer alle Raender) statt
Otsu + groesste Kontur.

Backend: Step-Nummern, Input-Bilder, Reprocess-Kaskade angepasst.
Frontend: PIPELINE_STEPS umgeordnet, Switch-Cases, Vorher-Bilder aktualisiert.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-lehrer/app/(admin)/ai/ocr-pipeline/page.tsx

@@ -71,8 +71,8 @@ export default function OcrPipelinePage() {
 
       // Determine which step to jump to based on current_step
       const dbStep = data.current_step || 1
-      // Steps: 1=deskew, 2=dewarp, 3=columns, ...
-      // UI steps are 0-indexed: 0=deskew, 1=dewarp, 2=columns, ...
+      // DB steps: 1=start, 2=orientation, 3=deskew, 4=dewarp, 5=crop, 6=columns, ...
+      // UI steps are 0-indexed: 0=orientation, 1=deskew, 2=dewarp, 3=crop, 4=columns, ...
       const uiStep = Math.max(0, dbStep - 1)
       const skipSteps = savedDocType?.skip_steps || []
 
@@ -205,8 +205,8 @@ export default function OcrPipelinePage() {
     handleNext()
   }
 
-  const handleDewarpNext = async () => {
-    // Auto-detect document type after dewarp, then advance
+  const handleCropNext = async () => {
+    // Auto-detect document type after crop (last image-processing step), then advance
     if (sessionId) {
       try {
         const res = await fetch(
@@ -273,9 +273,9 @@ export default function OcrPipelinePage() {
 
   const stepNames: Record<number, string> = {
     1: 'Orientierung',
-    2: 'Zuschneiden',
-    3: 'Begradigung',
-    4: 'Entzerrung',
+    2: 'Begradigung',
+    3: 'Entzerrung',
+    4: 'Zuschneiden',
     5: 'Spalten',
     6: 'Zeilen',
     7: 'Woerter',
@@ -312,11 +312,11 @@ export default function OcrPipelinePage() {
       case 0:
         return <StepOrientation sessionId={sessionId} onNext={handleOrientationComplete} />
       case 1:
-        return <StepCrop sessionId={sessionId} onNext={handleNext} />
-      case 2:
         return <StepDeskew sessionId={sessionId} onNext={handleNext} />
+      case 2:
+        return <StepDewarp sessionId={sessionId} onNext={handleNext} />
       case 3:
-        return <StepDewarp sessionId={sessionId} onNext={handleDewarpNext} />
+        return <StepCrop sessionId={sessionId} onNext={handleCropNext} />
       case 4:
         return <StepColumnDetection sessionId={sessionId} onNext={handleNext} />
       case 5:

admin-lehrer/app/(admin)/ai/ocr-pipeline/types.ts

@@ -310,9 +310,9 @@ export const IMAGE_STYLES: { value: ImageStyle; label: string }[] = [
 
 export const PIPELINE_STEPS: PipelineStep[] = [
   { id: 'orientation', name: 'Orientierung', icon: '🔄', status: 'pending' },
-  { id: 'crop', name: 'Zuschneiden', icon: '✂️', status: 'pending' },
   { id: 'deskew', name: 'Begradigung', icon: '📐', status: 'pending' },
   { id: 'dewarp', name: 'Entzerrung', icon: '🔧', status: 'pending' },
+  { id: 'crop', name: 'Zuschneiden', icon: '✂️', status: 'pending' },
   { id: 'columns', name: 'Spalten', icon: '📊', status: 'pending' },
   { id: 'rows', name: 'Zeilen', icon: '📏', status: 'pending' },
   { id: 'words', name: 'Woerter', icon: '🔤', status: 'pending' },

admin-lehrer/components/ocr-pipeline/StepCrop.tsx

@@ -78,7 +78,7 @@ export function StepCrop({ sessionId, onNext }: StepCropProps) {
     return <div className="text-sm text-gray-400">Keine Session ausgewaehlt.</div>
   }
 
-  const orientedUrl = `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/oriented`
+  const dewarpedUrl = `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/dewarped`
   const croppedUrl = cropResult
     ? `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/cropped`
     : null
@@ -95,12 +95,12 @@ export function StepCrop({ sessionId, onNext }: StepCropProps) {
 
       {/* Image comparison */}
       <ImageCompareView
-        originalUrl={orientedUrl}
+        originalUrl={dewarpedUrl}
         deskewedUrl={croppedUrl}
         showGrid={false}
         showBinarized={false}
         binarizedUrl={null}
-        leftLabel="Orientiert"
+        leftLabel="Entzerrt"
         rightLabel="Zugeschnitten"
       />
 

admin-lehrer/components/ocr-pipeline/StepDeskew.tsx

@@ -37,8 +37,8 @@ export function StepDeskew({ sessionId, onNext }: StepDeskewProps) {
           filename: data.filename,
           image_width: data.image_width,
           image_height: data.image_height,
-          // Use cropped image as "before" view
-          original_image_url: `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/cropped`,
+          // Use oriented image as "before" view (deskew runs right after orientation)
+          original_image_url: `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/oriented`,
         }
         setSession(sessionInfo)
 
@@ -155,7 +155,7 @@ export function StepDeskew({ sessionId, onNext }: StepDeskewProps) {
           showGrid={showGrid}
           showBinarized={showBinarized}
           binarizedUrl={deskewResult?.binarized_image_url ?? null}
-          leftLabel="Zugeschnitten"
+          leftLabel="Orientiert"
           rightLabel="Begradigt"
         />
       )}