diff --git a/core/pipeline.py b/core/pipeline.py
index 23e6364..18fdce9 100644
--- a/core/pipeline.py
+++ b/core/pipeline.py
@@ -10,6 +10,14 @@ from core.result import ComicResult, StepResult
 from processors.validator import validate_archive
 from processors.cleaner import clean_directory
 from processors.converter import needs_conversion, conversion_step_result
+from processors.checks import (
+    check_trash,
+    check_page_numbering,
+    check_image_extensions,
+    check_comicinfo,
+)
+from processors.page_normalizer import normalize_pages
+from processors.image_normalizer import normalize_images
 
 
 class Pipeline:
@@ -17,11 +25,13 @@ class Pipeline:
         self,
         steps: list,
         desired_format: str = "cbz",
+        desired_image_format: str = ".jpg",
         collision_policy: str = CollisionPolicy.ABORT,
         dry_run: bool = False,
     ):
         self.steps = steps
         self.desired_format = desired_format
+        self.desired_image_format = desired_image_format
         self.collision_policy = collision_policy
         self.dry_run = dry_run
 
@@ -41,7 +51,15 @@ class Pipeline:
         try:
             extract_archive(path, temp_dir)
 
-            # 3. Aplicar cada step sobre el directorio temporal
+            # 3. Ejecutar siempre los 4 content checks
+            step_results += [
+                check_trash(temp_dir),
+                check_page_numbering(temp_dir),
+                check_image_extensions(temp_dir),
+                check_comicinfo(temp_dir),
+            ]
+
+            # 4. Aplicar cada fix step sobre el directorio temporal
             any_changed = False
 
             if "clean" in self.steps:
@@ -50,6 +68,22 @@ class Pipeline:
                 if clean_result.changed:
                     any_changed = True
 
+            if "normalize_pages" in self.steps:
+                norm_result = normalize_pages(temp_dir)
+                step_results.append(norm_result)
+                if norm_result.changed:
+                    any_changed = True
+
+            if "normalize_images" in self.steps:
+                img_result = normalize_images(temp_dir, self.desired_image_format)
+                step_results.append(img_result)
+                if img_result.errors:
+                    return ComicResult(
+                        original_path=path, final_path=None, steps=step_results
+                    )
+                if img_result.changed:
+                    any_changed = True
+
             if "convert" in self.steps:
                 conv_result = conversion_step_result(real_format, self.desired_format)
                 step_results.append(conv_result)
@@ -60,7 +94,7 @@ class Pipeline:
                 if conv_result.changed:
                     any_changed = True
 
-            # 4. Reempaquetar si hubo cambios o conversión de formato
+            # 5. Reempaquetar si hubo cambios o conversión de formato
             needs_repack = any_changed or (
                 "convert" in self.steps
                 and needs_conversion(real_format, self.desired_format)
diff --git a/core/result.py b/core/result.py
index 73b98d8..a7daba0 100644
--- a/core/result.py
+++ b/core/result.py
@@ -31,6 +31,10 @@ class ComicResult:
             return f"OK [{self.original_path}] → {dest} ({', '.join(changed_steps)})"
         return f"OK [{self.original_path}] (sin cambios)"
 
+    def has_issues(self) -> bool:
+        """True si algún step tiene warnings o errors."""
+        return any(s.warnings or s.errors for s in self.steps)
+
     def full_report(self) -> str:
         lines = [f"Cómic: {self.original_path}"]
         for s in self.steps:
diff --git a/main.py b/main.py
index d0b3cde..48f1ec5 100644
--- a/main.py
+++ b/main.py
@@ -3,7 +3,6 @@
 import argparse
 from core.scanner import find_comic_files
 from core.pipeline import Pipeline
-from processors.validator import validate_comic
 
 
 def parse_args():
@@ -16,6 +15,9 @@ def parse_args():
     parser.add_argument("--convertir", action="store_true")
     parser.add_argument("--estandarizar", action="store_true")
     parser.add_argument("--formato", choices=["cbz", "cbr"], default="cbz")
+    parser.add_argument("--renumerar", action="store_true")
+    parser.add_argument("--uniformizar-imagenes", action="store_true")
+    parser.add_argument("--formato-imagen", choices=["jpg", "png", "webp"], default="jpg")
 
     return parser.parse_args()
 
@@ -30,19 +32,30 @@ def main():
             print(f)
 
     if args.validar:
+        pipeline = Pipeline(steps=[])
         for f in comic_files:
-            res = validate_comic(f)
-            print(f"{f} → {res.summary()}")
-            print()
+            result = pipeline.run(f)
+            if result.has_issues():
+                print(result.full_report())
+                print()
+        return
 
     steps = []
     if args.limpiar or args.estandarizar:
         steps.append("clean")
+    if args.renumerar:
+        steps.append("normalize_pages")
+    if args.uniformizar_imagenes:
+        steps.append("normalize_images")
     if args.convertir or args.estandarizar:
         steps.append("convert")
 
     if steps:
-        pipeline = Pipeline(steps=steps, desired_format=args.formato)
+        pipeline = Pipeline(
+            steps=steps,
+            desired_format=args.formato,
+            desired_image_format="." + args.formato_imagen,
+        )
         for f in comic_files:
             result = pipeline.run(f)
             print(result.summary())
diff --git a/processors/checks.py b/processors/checks.py
new file mode 100644
index 0000000..ed759a9
--- /dev/null
+++ b/processors/checks.py
@@ -0,0 +1,119 @@
+# processors/checks.py
+
+import os
+import re
+
+from core.constants import IMAGE_EXTENSIONS, TRASH_FILES
+from core.result import StepResult
+
+
+def check_trash(work_dir: str) -> StepResult:
+    """Detecta ficheros y directorios de basura presentes en el archivo."""
+    found = []
+    for root, dirs, files in os.walk(work_dir):
+        for name in files:
+            if name.lower() in TRASH_FILES:
+                found.append(os.path.relpath(os.path.join(root, name), work_dir))
+        for name in dirs:
+            if name.lower() in TRASH_FILES:
+                found.append(os.path.relpath(os.path.join(root, name), work_dir) + "/")
+
+    warnings = [f"Basura detectada: {f}" for f in found]
+    return StepResult(step="check_trash", changed=False, warnings=warnings)
+
+
+def _natural_sort_key(name: str):
+    parts = re.split(r"(\d+)", name)
+    return [int(p) if p.isdigit() else p.lower() for p in parts]
+
+
+def check_page_numbering(work_dir: str) -> StepResult:
+    """Detecta páginas mal numeradas: sin zero-padding, padding inconsistente, saltos."""
+    images = []
+    for root, _, files in os.walk(work_dir):
+        for f in files:
+            if os.path.splitext(f)[1].lower() in IMAGE_EXTENSIONS:
+                images.append(f)
+
+    images.sort(key=lambda f: _natural_sort_key(os.path.splitext(f)[0]))
+    total = len(images)
+    if total == 0:
+        return StepResult(step="check_page_numbering", changed=False)
+
+    warnings = []
+
+    # Extraer primer bloque numérico del stem de cada imagen
+    numeric_values = []
+    numeric_widths = []
+    for img in images:
+        stem = os.path.splitext(img)[0]
+        m = re.search(r"(\d+)", stem)
+        if m:
+            numeric_values.append(int(m.group(1)))
+            numeric_widths.append(len(m.group(1)))
+        else:
+            numeric_values.append(None)
+            numeric_widths.append(None)
+
+    has_numbers = [v for v in numeric_values if v is not None]
+    if not has_numbers:
+        return StepResult(step="check_page_numbering", changed=False)
+
+    # Comprobar zero-padding si hay >= 10 imágenes
+    if total >= 10:
+        required_width = len(str(total))
+        widths_set = set(w for w in numeric_widths if w is not None)
+        if len(widths_set) > 1:
+            warnings.append("Padding inconsistente entre páginas")
+        elif widths_set and min(widths_set) < required_width:
+            warnings.append(
+                f"Páginas no zero-padded: se necesita ancho {required_width}, "
+                f"encontrado {min(widths_set)}"
+            )
+
+    # Comprobar secuencia continua
+    sorted_values = sorted(v for v in numeric_values if v is not None)
+    if sorted_values:
+        first = sorted_values[0]
+        expected = list(range(first, first + len(sorted_values)))
+        if sorted_values != expected:
+            warnings.append("Páginas no secuenciales: hay saltos en la numeración")
+
+    return StepResult(step="check_page_numbering", changed=False, warnings=warnings)
+
+
+def check_image_extensions(work_dir: str) -> StepResult:
+    """Detecta mezcla de formatos de imagen en el archivo."""
+    ext_set = set()
+    for root, _, files in os.walk(work_dir):
+        for f in files:
+            ext = os.path.splitext(f)[1].lower()
+            if ext in IMAGE_EXTENSIONS:
+                # Normalizar .jpeg → .jpg
+                normalized = ".jpg" if ext == ".jpeg" else ext
+                ext_set.add(normalized)
+
+    warnings = []
+    if len(ext_set) > 1:
+        exts_str = ", ".join(sorted(ext_set))
+        warnings.append(f"Extensiones de imagen mezcladas: {exts_str}")
+
+    return StepResult(step="check_image_extensions", changed=False, warnings=warnings)
+
+
+def check_comicinfo(work_dir: str) -> StepResult:
+    """Detecta ausencia de ComicInfo.xml."""
+    warnings = []
+    found = False
+    for root, _, files in os.walk(work_dir):
+        for f in files:
+            if f.lower() == "comicinfo.xml":
+                found = True
+                break
+        if found:
+            break
+
+    if not found:
+        warnings.append("Falta ComicInfo.xml")
+
+    return StepResult(step="check_comicinfo", changed=False, warnings=warnings)
diff --git a/processors/cleaner.py b/processors/cleaner.py
index 1c5311b..2d290e4 100644
--- a/processors/cleaner.py
+++ b/processors/cleaner.py
@@ -1,6 +1,7 @@
 # processors/cleaner.py
 
 import os
+import shutil
 from core.constants import TRASH_FILES
 from core.result import StepResult
 
@@ -8,15 +9,21 @@ from core.result import StepResult
 def clean_directory(work_dir: str) -> StepResult:
     """
     Elimina TRASH_FILES del directorio ya extraído.
+    Elimina tanto ficheros como directorios de basura (e.g. __MACOSX).
     Sin I/O de archivo de cómic; trabaja sobre el directorio temporal.
     """
     removed = []
-    for root, _, files in os.walk(work_dir):
+    for root, dirs, files in os.walk(work_dir, topdown=False):
         for f in files:
             if f.lower() in TRASH_FILES:
                 full = os.path.join(root, f)
                 os.remove(full)
                 removed.append(os.path.relpath(full, work_dir))
+        for d in dirs:
+            if d.lower() in TRASH_FILES:
+                full = os.path.join(root, d)
+                shutil.rmtree(full, ignore_errors=True)
+                removed.append(os.path.relpath(full, work_dir) + "/")
 
     details = [f"Eliminado: {r}" for r in removed]
     return StepResult(
diff --git a/processors/image_normalizer.py b/processors/image_normalizer.py
new file mode 100644
index 0000000..f3ca1ae
--- /dev/null
+++ b/processors/image_normalizer.py
@@ -0,0 +1,68 @@
+# processors/image_normalizer.py
+
+import os
+
+from core.constants import IMAGE_EXTENSIONS
+from core.result import StepResult
+
+
+def normalize_images(work_dir: str, target_ext: str = ".jpg") -> StepResult:
+    """
+    Convierte todas las imágenes al formato indicado por target_ext.
+    Requiere Pillow. Si no está instalado, devuelve un StepResult con error.
+    """
+    try:
+        from PIL import Image
+    except ImportError:
+        return StepResult(
+            step="normalize_images",
+            changed=False,
+            errors=["Pillow no instalado. Ejecuta: pip install Pillow"],
+        )
+
+    target_ext = target_ext.lower()
+    if not target_ext.startswith("."):
+        target_ext = "." + target_ext
+
+    # Mapa de extensión a formato PIL
+    FORMAT_MAP = {
+        ".jpg": "JPEG",
+        ".jpeg": "JPEG",
+        ".png": "PNG",
+        ".webp": "WEBP",
+    }
+    pil_format = FORMAT_MAP.get(target_ext)
+    if pil_format is None:
+        return StepResult(
+            step="normalize_images",
+            changed=False,
+            errors=[f"Formato de imagen no soportado: {target_ext}"],
+        )
+
+    changed = False
+    details = []
+
+    for root, _, files in os.walk(work_dir):
+        for f in files:
+            ext = os.path.splitext(f)[1].lower()
+            normalized_ext = ".jpg" if ext == ".jpeg" else ext
+            if ext not in IMAGE_EXTENSIONS:
+                continue
+            if normalized_ext == target_ext:
+                continue
+
+            src = os.path.join(root, f)
+            stem = os.path.splitext(f)[0]
+            dst = os.path.join(root, stem + target_ext)
+
+            with Image.open(src) as img:
+                # Convertir modos incompatibles con JPEG
+                if pil_format == "JPEG" and img.mode in ("RGBA", "P", "LA"):
+                    img = img.convert("RGB")
+                img.save(dst, format=pil_format)
+
+            os.remove(src)
+            details.append(f"{f} → {stem + target_ext}")
+            changed = True
+
+    return StepResult(step="normalize_images", changed=changed, details=details)
diff --git a/processors/page_normalizer.py b/processors/page_normalizer.py
new file mode 100644
index 0000000..e31d406
--- /dev/null
+++ b/processors/page_normalizer.py
@@ -0,0 +1,57 @@
+# processors/page_normalizer.py
+
+import os
+import re
+
+from core.constants import IMAGE_EXTENSIONS
+from core.result import StepResult
+
+
+def _natural_sort_key(name: str):
+    parts = re.split(r"(\d+)", name)
+    return [int(p) if p.isdigit() else p.lower() for p in parts]
+
+
+def normalize_pages(work_dir: str) -> StepResult:
+    """
+    Renombra las imágenes del cómic a una numeración secuencial con zero-padding.
+    Fase 1: renombra a nombres temporales para evitar colisiones.
+    Fase 2: renombra a 001.ext, 002.ext… con ancho = len(str(total)).
+    """
+    # Recopilar imágenes con natural sort
+    images = []
+    for root, _, files in os.walk(work_dir):
+        for f in files:
+            ext = os.path.splitext(f)[1].lower()
+            if ext in IMAGE_EXTENSIONS:
+                images.append(os.path.join(root, f))
+
+    images.sort(key=lambda p: _natural_sort_key(os.path.splitext(os.path.basename(p))[0]))
+    total = len(images)
+    if total == 0:
+        return StepResult(step="normalize_pages", changed=False)
+
+    width = len(str(total))
+
+    # Fase 1: renombrar a temporales para evitar colisiones intermedias
+    temp_paths = []
+    for i, src in enumerate(images):
+        ext = os.path.splitext(src)[1].lower()
+        tmp = os.path.join(os.path.dirname(src), f".tmp_rename_{i}{ext}")
+        os.rename(src, tmp)
+        temp_paths.append(tmp)
+
+    # Fase 2: renombrar a nombre final
+    changed = False
+    details = []
+    for i, tmp in enumerate(temp_paths):
+        ext = os.path.splitext(tmp)[1].lower()
+        final_name = f"{str(i + 1).zfill(width)}{ext}"
+        final_path = os.path.join(os.path.dirname(tmp), final_name)
+        os.rename(tmp, final_path)
+        original_name = os.path.basename(images[i])
+        if original_name != final_name:
+            details.append(f"{original_name} → {final_name}")
+            changed = True
+
+    return StepResult(step="normalize_pages", changed=changed, details=details)
diff --git a/requirements.txt b/requirements.txt
index da04230..6736a7d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
-rarfile
\ No newline at end of file
+rarfile
+Pillow
\ No newline at end of file