Classifies an image as Authentic or Forged by fusing raw RGB pixels (frozen ResNet50) with an Error Level Analysis (ELA) map (custom CNN) that amplifies JPEG compression inconsistencies left by tampering.
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Classifies an image as Authentic or Forged by fusing raw RGB pixels (frozen ResNet50) with an Error Level Analysis (ELA) map (custom CNN) that amplifies JPEG compression inconsistencies left by tampering.
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1 QuelleVerifiziert 10. Sept.
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2 AuszügeM3_best_v2.h5 (~98 MB, full Keras 3 model) · License: MIT[rgb 224×224×3, ela 224×224×3]CASIA v2 (7,492 authentic + 5,124 tampered; 70/15/15 stratified split, SEED 42), Adam (lr 0.001), BCE loss, batch 32, Colab GPU. Decision threshold = 0.50.
| Metric | Value | Ablation | AUC-ROC | |
|---|---|---|---|---|
| AUC-ROC (test) | 0.9774 | RGB only | 0.5822 | |
| Test accuracy | ~92% | ELA only | 0.9807 | |
| Error rate | ~8% | Dual (M3) | 0.9774 |
The model is fundamentally ELA-driven (RGB alone ≈ random); ResNet50 adds texture context.
OOD: high-quality phone photos (HDR/multi-frame) yield large ELA residuals → often flagged forged. Scope: CASIA-only — won't generalise to GANs, deepfakes, or inpainting; ResNet50 stays frozen (no fine-tuning).
ELA must match training exactly: JPEG q=90 → diff → 15× brightness → JPEG q=75 → tf.image.decode_jpeg → bilinear resize → ÷255.
import io, numpy as np, tensorflow as tf
from PIL import Image, ImageChops, ImageEnhance
from huggingface_hub import hf_hub_download
IMG = (224, 224)
model = tf.keras.models.load_model(hf_hub_download(
repo_id="salmanzaman777/digital-image-forgery-detection-model",
filename="M3_best_v2.h5"), compile=False)
def ela(img, q=90, scale=15):
img = img.convert("RGB"); buf = io.BytesIO(); img.save(buf, "JPEG", quality=q); buf.seek(0)
d = ImageEnhance.Brightness(ImageChops.difference(img, Image.open(buf).convert("RGB"))).enhance(scale)
out = io.BytesIO(); d.save(out, "JPEG", quality=75)
x = tf.image.resize(tf.image.decode_jpeg(out.getvalue(), channels=3), IMG)
return (tf.cast(x, tf.float32) / 255.0).numpy()
image = Image.open("test.jpg").convert("RGB")
rgb = np.array(image.resize(IMG, Image.LANCZOS), np.float32)[np.newaxis] / 255.0
pred = float(model.predict([rgb, ela(image)[np.newaxis]], verbose=0)[0][0])
print("FORGED" if pred > 0.5 else "AUTHENTIC", f"(score={pred:.4f})")
--- license: mit library_name: keras pipeline_tag: image-classification tags: - image-forensics - forgery-detection - error-level-analysis --- # M3 — Dual-Branch CNN for Image Forgery Detection Classifies an image as **Authentic** or **Forged** by fusing raw RGB pixels (frozen ResNet50) with an **Error Level Analysis (ELA)** map (custom CNN) that amplifies JPEG compression inconsistencies left by tampering. - **For:** NED University — PG Diploma in Generative AI (*Deep Learning*) - **By:** Mr. Salman Zaman and Mr. Muhammad Usama Alam · Coordinator: Mr. Sajid Majeed - **File:** `M3_best_v2.h5` (~98 MB, full Keras 3 model) · **License:** MIT - **Demo:** [salmanzaman777/digital-image-forgery-detector](https://huggingface.co/spaces/salmanzaman777/digital-image-forgery-detector) ## Architecture · two inputs `[rgb 224×224×3, ela 224×224×3]` - **RGB:** frozen ResNet50 (ImageNet) → GlobalAvgPool → 2048-d - **ELA:** 3× (Conv2D + BN + MaxPool, 32→64→128) → GlobalAvgPool → 128-d - **Head:** Concatenate (2176-d) → Dense(256, ReLU) → Dropout(0.5) → Dense(1, Sigmoid) · ~24.24M params / ~652K trainable ## Training & Evaluation **CASIA v2** (7,492 authentic + 5,124 tampered; 70/15/15 stratified split, SEED 42), Adam (lr 0.001), BCE loss, batch 32, Colab GPU. Decision threshold = **0.50**. | Metric | Value | | Ablation | AUC-ROC | |---|---|---|---|---| | AUC-ROC (test) | **0.9774** | | RGB only | 0.5822 | | Test accuracy | ~92% | | ELA only | 0.9807 | | Error rate | ~8% | | **Dual (M3)** | **0.9774** | The model is fundamentally **ELA-driven** (RGB alone ≈ random); ResNet50 adds texture context. ## Limitations **OOD:** high-quality phone photos (HDR/multi-frame) yield large ELA residuals → often flagged forged. **Scope:** CASIA-only — won't generalise to GANs, deepfakes, or inpainting; ResNet50 stays frozen (no fine-tuning). ## Usage ELA must match training exactly: JPEG q=90 → diff → 15× brightness → JPEG q=75 → `tf.image.decode_jpeg` → bilinear resize → ÷255. ```python import io, numpy as np, tensorflow as tf from PIL import Image, ImageChops, ImageEnhance from huggingface_hub import hf_hub_download IMG = (224, 224) model = tf.keras.models.load_model(hf_hub_download( repo_id="salmanzaman777/digital-image-forgery-detection-model", filename="M3_best_v2.h5"), compile=False) def ela(img, q=90, scale=15): img = img.convert("RGB"); buf = io.BytesIO(); im...
Source context: 0 downloads · 0 likes · Pipeline image-classification · Library keras · Repo salmanzaman777/digital-image-forgery-detection-model