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End-to-End Multimodal Data Augmentation and Adversarial Robustness Benchmark with AugLy for Images, Text, Audio, and PyTorch

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In this tutorial, we build a comprehensive multimodal augmentation and robustness workflow with AugLy for images, text, and audio. We start by addressing modern dependency compatibility issues and generating deterministic synthetic datasets so the experiments remain self-contained and reproducible. We then explore AugLy’s functional and class-based APIs, metadata, and intensity tracking, probabilistic composition, bounding-box-aware transformations, and custom transforms. We extend the workflow into practical robustness experiments by benchmarking perceptual-hash copy detection under image distortions and evaluating text classifiers against adversarial perturbations, Unicode obfuscation, sanitization, and adversarial training. We also integrate audio augmentation, build a queryable metadata warehouse, and connect AugLy transformations directly to PyTorch datasets and DataLoaders, giving us an end-to-end view of augmentation as both a data-generation mechanism and a measurable robustness tool.

import subprocess, sys, importlib
def _sh(cmd):
   print(f"$ {cmd}")
   subprocess.run(cmd, shell=True, check=False,
                  stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
def _need(mod):
   try:
       importlib.import_module(mod)
       return False
   except ImportError:
       return True
if _need("augly"):
   _sh("apt-get -qq install -y libmagic1 > /dev/null 2>&1")
   _sh(f'"{sys.executable}" -m pip install -q --no-deps augly')
   _sh(f'"{sys.executable}" -m pip install -q "iopath>=0.1.8" "python-magic>=0.4.22" '
       f'"regex>=2021.4.4" "nlpaug==1.1.3"')
import numpy as np
from PIL import Image, ImageDraw, ImageFont, ImageFilter
for _name, _builtin in (("float", float), ("int", int), ("bool", bool)):
   if not hasattr(np, _name):
       setattr(np, _name, _builtin)
def _size(font, text):
   left, top, right, bottom = font.getbbox(text)
   return (right, bottom)
if not hasattr(ImageFont.FreeTypeFont, "getsize"):
   ImageFont.FreeTypeFont.getsize = lambda self, t, *a, **k: _size(self, t)
if not hasattr(ImageFont.FreeTypeFont, "getsize_multiline"):
   def _getsize_multiline(self, text, direction=None, spacing=4, features=None,
                          language=None, stroke_width=0):
       lines = text.split("\n")
       w = max((_size(self, ln)[0] for ln in lines), default=0)
       h = sum(_size(self, ln)[1] for ln in lines) + spacing * (len(lines) - 1)
       return (w, h)
   ImageFont.FreeTypeFont.getsize_multiline = _getsize_multiline
import os, io, json, math, random, string, textwrap, unicodedata, warnings
from dataclasses import dataclass
from typing import Any, Dict, List, Optional, Tuple
import matplotlib.pyplot as plt
import pandas as pd
import augly.image as imaugs
import augly.text as textaugs
import augly.utils as augutils
from augly.image.transforms import BaseTransform as ImageBaseTransform
warnings.filterwarnings("ignore")
pd.set_option("display.width", 160)
SEED = 1234
random.seed(SEED)
np.random.seed(SEED)
print("\n" + "=" * 78)
print("AugLy ready.  assets at:", augutils.ASSETS_BASE_DIR)
print("image augs :", len([f for f in dir(imaugs) if f[0].islower()]))
print("text  augs :", len([f for f in dir(textaugs) if f[0].islower()]))
print("=" * 78 + "\n")
def make_image(idx: int, w: int = 320, h: int = 240) -> Tuple[Image.Image, Tuple[int, int, int, int]]:
   """Procedurally generated 'photo' + a ground-truth bbox in pascal_voc format."""
   rng = random.Random(SEED + idx)
   img = Image.new("RGB", (w, h), tuple(rng.randint(20, 90) for _ in range(3)))
   d = ImageDraw.Draw(img)
   for _ in range(70):
       x0, y0 = rng.randint(0, w), rng.randint(0, h)
       d.line([x0, y0, x0 + rng.randint(-60, 60), y0 + rng.randint(-60, 60)],
              fill=tuple(rng.randint(60, 160) for _ in range(3)), width=rng.randint(1, 3))
   ow, oh = rng.randint(70, 130), rng.randint(60, 110)
   ox, oy = rng.randint(10, w - ow - 10), rng.randint(10, h - oh - 10)
   box = (ox, oy, ox + ow, oy + oh)
   colour = tuple(rng.randint(150, 255) for _ in range(3))
   if idx % 3 == 0:
       d.ellipse(box, fill=colour, outline=(255, 255, 255), width=3)
   elif idx % 3 == 1:
       d.rectangle(box, fill=colour, outline=(255, 255, 255), width=3)
   else:
       d.polygon([(ox + ow // 2, oy), (ox + ow, oy + oh), (ox, oy + oh)],
                 fill=colour, outline=(255, 255, 255))
   return img, box
N_IMAGES = 24
IMAGES, BOXES = zip(*[make_image(i) for i in range(N_IMAGES)])
IMAGES, BOXES = list(IMAGES), list(BOXES)
DEMO_IMG, DEMO_BOX = IMAGES[0], BOXES[0]
def make_text_dataset(n_per_class: int = 260):
   """Tiny sentiment corpus built from templates -> learnable but not trivial."""
   rng = random.Random(SEED)
   pos_adj = ["excellent", "delightful", "superb", "charming", "brilliant",
              "flawless", "wonderful", "outstanding", "impressive", "lovely"]
   neg_adj = ["terrible", "awful", "dreadful", "disappointing", "clumsy",
              "broken", "miserable", "useless", "painful", "sloppy"]
   subj = ["the movie", "this restaurant", "the hotel room", "their support team",
           "the new phone", "the sequel", "this laptop", "the delivery service"]
   tail_p = ["and I would recommend it to anyone", "worth every rupee",
             "I left completely satisfied", "easily the best of the year",
             "it exceeded all my expectations"]
   tail_n = ["and I want a refund", "a total waste of money",
             "I left extremely frustrated", "easily the worst of the year",
             "it failed every expectation"]
   rows = []
   for _ in range(n_per_class):
       rows.append((f"{rng.choice(subj)} was {rng.choice(pos_adj)} {rng.choice(tail_p)}", 1))
       rows.append((f"{rng.choice(subj)} was {rng.choice(neg_adj)} {rng.choice(tail_n)}", 0))
   rng.shuffle(rows)
   return [r[0] for r in rows], [r[1] for r in rows]
TEXTS, LABELS = make_text_dataset()
DEMO_TEXT = "The quick brown fox jumps over the lazy dog near the river bank"
def make_audio(seconds: float = 2.0, sr: int = 16000) -> Tuple[np.ndarray, int]:
   """A chirp + harmonics + a little noise = something you can actually hear change."""
   t = np.linspace(0, seconds, int(sr * seconds), endpoint=False)
   f = np.linspace(220, 880, t.size)
   sig = 0.5 * np.sin(2 * np.pi * f * t) + 0.2 * np.sin(2 * np.pi * 2 * f * t)
   sig += 0.02 * np.random.RandomState(SEED).randn(t.size)
   env = np.minimum(1.0, np.minimum(t * 8, (seconds - t) * 8))
   return (sig * env).astype(np.float32), sr
AUDIO, SR = make_audio()
def show_grid(pairs, cols=4, title="", figsize_scale=2.9):
   """pairs: list of (caption, PIL.Image)."""
   rows = math.ceil(len(pairs) / cols)
   fig, axes = plt.subplots(rows, cols, figsize=(cols * figsize_scale, rows * figsize_scale))
   axes = np.atleast_1d(axes).ravel()
   for ax, (cap, im) in zip(axes, pairs):
       ax.imshow(im)
       ax.set_title(cap, fontsize=8)
       ax.axis("off")
   for ax in axes[len(pairs):]:
       ax.axis("off")
   if title:
       fig.suptitle(title, fontsize=13, y=1.0)
   plt.tight_layout()
   plt.show()
def as_str(out) -> str:
   """AugLy text augs return str for str input in some transforms, list in others."""
   return out[0] if isinstance(out, list) else out
print("\n### §2  IMAGE AUGMENTATION + METADATA " + "#" * 38)
functional_result = imaugs.pixelization(DEMO_IMG, ratio=0.25)
class_result = imaugs.Pixelization(ratio=0.25, p=1.0)(DEMO_IMG)
print("functional == class:", np.array_equal(np.array(functional_result), np.array(class_result)))
IMAGE_ZOO = {
   "blur":               lambda im, m: imaugs.blur(im, radius=3.0, metadata=m),
   "brightness":         lambda im, m: imaugs.brightness(im, factor=1.7, metadata=m),
   "color_jitter":       lambda im, m: imaugs.color_jitter(im, brightness_factor=1.3,
                                                           contrast_factor=1.4,
                                                           saturation_factor=1.6, metadata=m),
   "crop":               lambda im, m: imaugs.crop(im, x1=.15, y1=.15, x2=.85, y2=.85, metadata=m),
   "encoding_quality":   lambda im, m: imaugs.encoding_quality(im, quality=8, metadata=m),
   "grayscale":          lambda im, m: imaugs.grayscale(im, metadata=m),
   "hflip":              lambda im, m: imaugs.hflip(im, metadata=m),
   "meme_format":        lambda im, m: imaugs.meme_format(im, text="TOP TEXT",
                                                          caption_height=90, metadata=m),
   "opacity":            lambda im, m: imaugs.opacity(im, level=0.45, metadata=m),
   "overlay_emoji":      lambda im, m: imaugs.overlay_emoji(im, opacity=0.9,
                                                            emoji_size=0.35, metadata=m),
   "overlay_screenshot": lambda im, m: imaugs.overlay_onto_screenshot(im, metadata=m),
   "overlay_stripes":    lambda im, m: imaugs.overlay_stripes(im, line_width=0.4,
                                                              line_opacity=0.7, metadata=m),
   "overlay_text":       lambda im, m: imaugs.overlay_text(im, opacity=0.9, metadata=m),
   "pad_square":         lambda im, m: imaugs.pad_square(im, metadata=m),
   "perspective":        lambda im, m: imaugs.perspective_transform(im, sigma=40.0, metadata=m),
   "pixelization":       lambda im, m: imaugs.pixelization(im, ratio=0.15, metadata=m),
   "random_noise":       lambda im, m: imaugs.random_noise(im, var=0.03, metadata=m),
   "rotate":             lambda im, m: imaugs.rotate(im, degrees=17, metadata=m),
   "saturation":         lambda im, m: imaugs.saturation(im, factor=3.0, metadata=m),
   "scale":              lambda im, m: imaugs.scale(im, factor=0.35, metadata=m),
   "sharpen":            lambda im, m: imaugs.sharpen(im, factor=8.0, metadata=m),
   "shuffle_pixels":     lambda im, m: imaugs.shuffle_pixels(im, factor=0.15, metadata=m),
   "skew":               lambda im, m: imaugs.skew(im, skew_factor=0.35, metadata=m),
   "vflip":              lambda im, m: imaugs.vflip(im, metadata=m),
}
gallery, image_meta = [("ORIGINAL", DEMO_IMG)], []
for name, fn in IMAGE_ZOO.items():
   m = []
   try:
       out = fn(DEMO_IMG, m)
       gallery.append((f"{name}\nintensity={m[0]['intensity']:.1f}", out))
       image_meta.append(m[0])
   except Exception as e:
       print(f"  [skip] {name}: {type(e).__name__}: {e}")
show_grid(gallery, cols=5, title="§2  AugLy image augmentations (with AugLy's own intensity score)")
meta_df = pd.DataFrame(image_meta)[["name", "intensity", "src_width", "src_height",
                                   "dst_width", "dst_height"]]
print(meta_df.sort_values("intensity", ascending=False).head(10).to_string(index=False))

We set up AugLy in a modern Colab environment while adding compatibility shims for NumPy and Pillow. We generate deterministic synthetic image, text, and audio datasets without external downloads. We also initialize reusable visualization and utility functions before exploring image augmentation and metadata.

print("\n### §3  COMPOSITION & REPRODUCIBILITY " + "#" * 39)
REUPLOAD_PIPELINE = imaugs.Compose([
   imaugs.OneOf([
       imaugs.OverlayOntoScreenshot(),
       imaugs.MemeFormat(text="LOL", caption_height=80),
       imaugs.OverlayStripes(line_width=0.3, line_opacity=0.5),
   ], p=0.9),
   imaugs.RandomAspectRatio(min_ratio=0.7, max_ratio=1.4, p=0.5),
   imaugs.RandomEmojiOverlay(p=0.7),
   imaugs.RandomBrightness(min_factor=0.7, max_factor=1.4, p=0.6),
   imaugs.EncodingQuality(quality=12, p=1.0),
])
def run_pipeline(img, seed=None):
   """AugLy image transforms use the global `random` module -> seed it for determinism."""
   if seed is not None:
       random.seed(seed)
       np.random.seed(seed)
   meta = []
   return REUPLOAD_PIPELINE(img, metadata=meta), meta
a, meta_a = run_pipeline(DEMO_IMG, seed=7)
b, meta_b = run_pipeline(DEMO_IMG, seed=7)
c, _ = run_pipeline(DEMO_IMG, seed=99)
print("same seed -> identical output:", np.array_equal(np.array(a), np.array(b)))
print("applied chain (seed=7)      :", " -> ".join(m["name"] for m in meta_a))
show_grid([("original", DEMO_IMG), ("seed=7", a), ("seed=7 again", b), ("seed=99", c)],
         cols=4, title="§3  Seeded, reproducible augmentation pipelines")
print("\n### §4  BBOX-AWARE AUGMENTATION " + "#" * 45)
BBOX_OPS = [
   ("crop",        lambda im, m, bb: imaugs.crop(im, x1=.1, y1=.1, x2=.9, y2=.9,
                                                 metadata=m, bboxes=bb, bbox_format="pascal_voc")),
   ("hflip",       lambda im, m, bb: imaugs.hflip(im, metadata=m, bboxes=bb,
                                                  bbox_format="pascal_voc")),
   ("rotate 20",   lambda im, m, bb: imaugs.rotate(im, degrees=20, metadata=m, bboxes=bb,
                                                   bbox_format="pascal_voc")),
   ("pad",         lambda im, m, bb: imaugs.pad(im, w_factor=0.25, h_factor=0.25,
                                                metadata=m, bboxes=bb, bbox_format="pascal_voc")),
   ("meme_format", lambda im, m, bb: imaugs.meme_format(im, text="BOXED", caption_height=80,
                                                        metadata=m, bboxes=bb,
                                                        bbox_format="pascal_voc")),
]
def draw_box(img, box, colour=(0, 255, 0)):
   out = img.copy().convert("RGB")
   ImageDraw.Draw(out).rectangle([float(v) for v in box], outline=colour, width=4)
   return out
bbox_panels = [("original", draw_box(DEMO_IMG, DEMO_BOX))]
for label, op in BBOX_OPS:
   m = []
   try:
       out = op(DEMO_IMG, m, [DEMO_BOX])
       dst = m[0]["dst_bboxes"][0]
       bbox_panels.append((f"{label}\n{tuple(round(v) for v in dst)}", draw_box(out, dst)))
       print(f"  {label:12s} {DEMO_BOX} -> {tuple(round(v, 1) for v in dst)}")
   except Exception as e:
       print(f"  [skip] {label}: {type(e).__name__}: {e}")
show_grid(bbox_panels, cols=3, title="§4  Boxes follow the pixels automatically")
print("\n### §5  CUSTOM TRANSFORMS " + "#" * 51)
class RecompressionChain(ImageBaseTransform):
   """Simulate an image surviving N rounds of platform re-encoding.
   Subclassing BaseTransform (rather than using ApplyLambda) buys you: the `p`
   probability gate, `force=True`, and full participation in Compose/OneOf.
   """
   def __init__(self, n_rounds: int = 3, min_q: int = 12, max_q: int = 45,
                downscale: float = 0.85, p: float = 1.0):
       super().__init__(p)
       self.n_rounds, self.min_q, self.max_q, self.downscale = n_rounds, min_q, max_q, downscale
   def apply_transform(self, image, metadata=None, bboxes=None, bbox_format=None):
       src_w, src_h = image.size
       out, qualities = image, []
       for _ in range(self.n_rounds):
           q = random.randint(self.min_q, self.max_q)
           qualities.append(q)
           out = imaugs.encoding_quality(out, quality=q)
           out = imaugs.scale(out, factor=self.downscale)
       out = out.resize((src_w, src_h), Image.BILINEAR)
       if metadata is not None:
           metadata.append({
               "name": "recompression_chain",
               "src_width": src_w, "src_height": src_h,
               "dst_width": out.size[0], "dst_height": out.size[1],
               "n_rounds": self.n_rounds, "qualities": qualities,
               "intensity": float(100 * (1 - np.mean(qualities) / 100)),
           })
       return out
vignette = imaugs.ApplyLambda(aug_function=lambda im: Image.composite(
   im, Image.new("RGB", im.size, (0, 0, 0)),
   Image.radial_gradient("L").resize(im.size).point(lambda v: 255 - v)))
random.seed(SEED)
custom_meta = []
show_grid([
   ("original", DEMO_IMG),
   ("RecompressionChain(n=3)", RecompressionChain(n_rounds=3)(DEMO_IMG, metadata=custom_meta)),
   ("RecompressionChain(n=6)", RecompressionChain(n_rounds=6, min_q=5, max_q=20)(DEMO_IMG)),
   ("ApplyLambda vignette", vignette(DEMO_IMG)),
], cols=4, title="§5  Custom transforms drop straight into the AugLy API")
print("  custom metadata:", custom_meta[0])
CUSTOM_PIPELINE = imaugs.Compose([RecompressionChain(n_rounds=2, p=1.0),
                                 imaugs.RandomEmojiOverlay(p=1.0)])
_ = CUSTOM_PIPELINE(DEMO_IMG)
print("  composed with built-ins: OK")

We construct probabilistic augmentation pipelines with Compose and OneOf while controlling reproducibility through explicit random seeds. We demonstrate how AugLy automatically propagates bounding-box coordinates through spatial transformations. We then implement a custom BaseTransform and combine it with built-in AugLy transforms.

print("\n### §6  COPY-DETECTION ROBUSTNESS BENCHMARK " + "#" * 33)
from scipy.fftpack import dct
def phash(img: Image.Image, hash_size: int = 8, highfreq: int = 4) -> np.ndarray:
   """Classic DCT perceptual hash -> 64-bit signature as a bool array."""
   size = hash_size * highfreq
   px = np.asarray(img.convert("L").resize((size, size), Image.LANCZOS), dtype=np.float64)
   d = dct(dct(px, axis=0, norm="ortho"), axis=1, norm="ortho")[:hash_size, :hash_size]
   return (d > np.median(d[1:, 1:])).ravel()
def hamming(a, b) -> int:
   return int(np.count_nonzero(a != b))
INDEX = np.stack([phash(im) for im in IMAGES])
ATTACKS = {
   "brightness x1.6":    lambda im: imaugs.brightness(im, factor=1.6),
   "blur r=3":           lambda im: imaugs.blur(im, radius=3.0),
   "jpeg q=8":           lambda im: imaugs.encoding_quality(im, quality=8),
   "crop 80%":           lambda im: imaugs.crop(im, x1=.1, y1=.1, x2=.9, y2=.9),
   "rotate 12":          lambda im: imaugs.rotate(im, degrees=12),
   "hflip":              lambda im: imaugs.hflip(im),
   "grayscale":          lambda im: imaugs.grayscale(im),
   "pixelize 0.2":       lambda im: imaugs.pixelization(im, ratio=0.2),
   "