Files
PaintPlus/backend/app/services/upscale.py
T
Claude cea9ee9d6c Smart upscale: auto-detect hardware and pick best Real-ESRGAN path
Detection priority (probed once, cached):
  1. Real-ESRGAN PyTorch + CUDA GPU   → fastest, best quality
  2. Real-ESRGAN PyTorch + Apple MPS  → fast on Apple Silicon
  3. Real-ESRGAN NCNN Vulkan binary   → fast on any GPU via Vulkan (no CUDA needed)
  4. Real-ESRGAN PyTorch CPU          → works, slow (warned in UI)
  5. Lanczos                          → always available, instant fallback

Backend:
- services/upscale.py: full capability probe (probe_upscale_capabilities),
  implementations for PyTorch (CUDA/MPS/CPU auto-device) and NCNN binary,
  upscale_sync() resolves method with fallback chain,
  async upscale_image() runs in thread pool
- print_tools.py: /api/print/upscale uses new service; method="auto" by default;
  GET /api/print/upscale/available returns full capability map with device info
  and recommended_label; POST /api/print/upscale/refresh-caps busts cache
  without restart (useful after installing NCNN binary into container)

Frontend:
- upscale.js: fetches capability map on first open; builds method selector showing
  only available options; labels recommended method with ★; shows device info
  (CUDA/MPS/CPU/NCNN) in dialog; maps display label back to method key on submit;
  shows actual method used in success toast and undo history entry

Scripts:
- scripts/download_realesrgan.py: downloads NCNN Vulkan binary for current platform
  (Linux/macOS/Windows) to /app/data/models/realesrgan/; makes executable;
  run inside container or locally

https://claude.ai/code/session_01B58MaJCU1R6KwBDJCp8AfN
2026-06-09 18:32:32 +00:00

301 lines
11 KiB
Python

"""
Upscale service — auto-detects best available method and runs it.
Priority (auto mode):
1. Real-ESRGAN PyTorch + CUDA GPU — fastest, best quality
2. Real-ESRGAN PyTorch + Apple MPS — fast on Apple Silicon
3. Real-ESRGAN NCNN Vulkan binary — fast on any GPU (Intel/AMD/integrated)
4. Real-ESRGAN PyTorch CPU — works, slow (warn user)
5. Lanczos — always available, instant
Capability probe is run once at first call and cached.
"""
import asyncio
import os
import shutil
import subprocess
import sys
import tempfile
from io import BytesIO
from pathlib import Path
from typing import Optional
from PIL import Image
# ── Capability detection ──────────────────────────────────────────────────────
_caps: Optional[dict] = None
def probe_upscale_capabilities() -> dict:
"""
Detect what upscaling hardware and software is available.
Result is cached after first call.
"""
global _caps
if _caps is not None:
return _caps
caps = {
"lanczos": True,
"realesrgan_pytorch": False,
"realesrgan_pytorch_device": None, # "cuda" | "mps" | "cpu"
"realesrgan_ncnn": False,
"realesrgan_ncnn_path": None,
"recommended": "lanczos",
"recommended_label": "Lanczos (no AI upscaler found)",
"methods": ["lanczos"],
}
# ── PyTorch path ──────────────────────────────────────────────────────────
pytorch_device = None
try:
import torch
if torch.cuda.is_available():
pytorch_device = "cuda"
elif hasattr(torch.backends, "mps") and torch.backends.mps.is_available():
pytorch_device = "mps"
else:
pytorch_device = "cpu"
except ImportError:
pass
if pytorch_device:
try:
import realesrgan # noqa: F401
from basicsr.archs.rrdbnet_arch import RRDBNet # noqa: F401
caps["realesrgan_pytorch"] = True
caps["realesrgan_pytorch_device"] = pytorch_device
caps["methods"].append("realesrgan_pytorch")
except ImportError:
pass
# ── NCNN Vulkan binary ────────────────────────────────────────────────────
ncnn_path = _find_ncnn_binary()
if ncnn_path:
caps["realesrgan_ncnn"] = True
caps["realesrgan_ncnn_path"] = str(ncnn_path)
caps["methods"].append("realesrgan_ncnn")
# ── Pick recommended ──────────────────────────────────────────────────────
if caps["realesrgan_pytorch"] and pytorch_device in ("cuda", "mps"):
device_label = "CUDA GPU" if pytorch_device == "cuda" else "Apple Silicon"
caps["recommended"] = "realesrgan_pytorch"
caps["recommended_label"] = f"Real-ESRGAN ({device_label})"
elif caps["realesrgan_ncnn"]:
caps["recommended"] = "realesrgan_ncnn"
caps["recommended_label"] = "Real-ESRGAN NCNN (Vulkan)"
elif caps["realesrgan_pytorch"] and pytorch_device == "cpu":
caps["recommended"] = "realesrgan_pytorch"
caps["recommended_label"] = "Real-ESRGAN (CPU — may be slow)"
else:
caps["recommended"] = "lanczos"
caps["recommended_label"] = "Lanczos (install Real-ESRGAN for AI quality)"
_caps = caps
return caps
def _find_ncnn_binary() -> Optional[Path]:
"""Find realesrgan-ncnn-vulkan binary on the system."""
# Check PATH first
found = shutil.which("realesrgan-ncnn-vulkan")
if found:
return Path(found)
# Check known install locations
candidates = [
Path("/app/data/models/realesrgan/realesrgan-ncnn-vulkan"),
Path("/usr/local/bin/realesrgan-ncnn-vulkan"),
Path.home() / ".local/bin/realesrgan-ncnn-vulkan",
# Windows
Path(r"C:/realesrgan-ncnn-vulkan/realesrgan-ncnn-vulkan.exe"),
# macOS Homebrew
Path("/opt/homebrew/bin/realesrgan-ncnn-vulkan"),
Path("/usr/local/bin/realesrgan-ncnn-vulkan"),
]
for p in candidates:
if p.exists() and os.access(p, os.X_OK):
return p
return None
def invalidate_caps_cache():
"""Call after installing new software so next probe picks it up."""
global _caps
_caps = None
# ── Upscale implementations ───────────────────────────────────────────────────
def _to_png_bytes(img: Image.Image) -> bytes:
buf = BytesIO()
img.save(buf, format="PNG")
return buf.getvalue()
def upscale_lanczos(image: Image.Image, scale: float) -> tuple[bytes, str]:
"""Pure Pillow Lanczos — instant, always available."""
new_w = round(image.width * scale)
new_h = round(image.height * scale)
result = image.resize((new_w, new_h), Image.Resampling.LANCZOS)
return _to_png_bytes(result), "lanczos"
def upscale_realesrgan_pytorch(image: Image.Image, scale: float) -> tuple[bytes, str]:
"""
Real-ESRGAN via PyTorch.
Uses CUDA > MPS > CPU automatically based on what's available.
Scale factors: any float — upscales to nearest 2x or 4x model, then resizes to exact target.
"""
import torch
from basicsr.archs.rrdbnet_arch import RRDBNet
from realesrgan import RealESRGANer
caps = probe_upscale_capabilities()
device = caps.get("realesrgan_pytorch_device", "cpu")
# Choose model: x2 for scale <= 2.5, x4 otherwise
model_scale = 2 if scale <= 2.5 else 4
model = RRDBNet(
num_in_ch=3, num_out_ch=3, num_feat=64,
num_block=23, num_grow_ch=32, scale=model_scale
)
# Model path: check local cache first, then let RealESRGANer auto-download
model_dir = Path("/app/data/models/realesrgan")
model_dir.mkdir(parents=True, exist_ok=True)
model_name = f"RealESRGAN_x{model_scale}plus.pth"
model_path = model_dir / model_name
if not model_path.exists():
model_path = None # RealESRGANer will download to its default cache
upsampler = RealESRGANer(
scale=model_scale,
model_path=str(model_path) if model_path else None,
model=model,
tile=512,
tile_pad=10,
pre_pad=0,
half=(device == "cuda"), # fp16 only on CUDA
device=torch.device(device),
)
import numpy as np
img_bgr = np.array(image)[:, :, ::-1].copy() # RGB→BGR
enhanced, _ = upsampler.enhance(img_bgr, outscale=scale)
result = Image.fromarray(enhanced[:, :, ::-1]) # BGR→RGB
label = f"realesrgan_pytorch_{device}"
return _to_png_bytes(result), label
def upscale_realesrgan_ncnn(image: Image.Image, scale: float) -> tuple[bytes, str]:
"""
Real-ESRGAN via NCNN Vulkan binary — works on any GPU (Intel/AMD/integrated/Apple).
Runs as subprocess with temp file I/O.
"""
caps = probe_upscale_capabilities()
binary = caps.get("realesrgan_ncnn_path")
if not binary:
raise RuntimeError("realesrgan-ncnn-vulkan binary not found")
# NCNN only supports integer scales (2, 3, 4) natively
# For non-integer scales: upscale to nearest integer, then resize to exact target
model_scale = 4 if scale > 2.5 else 2
target_w = round(image.width * scale)
target_h = round(image.height * scale)
with tempfile.TemporaryDirectory() as tmpdir:
in_path = Path(tmpdir) / "input.png"
out_path = Path(tmpdir) / "output.png"
image.save(in_path, format="PNG")
# Model name for NCNN (bundled with binary)
model_name = f"realesrgan-x{model_scale}plus"
cmd = [
binary,
"-i", str(in_path),
"-o", str(out_path),
"-s", str(model_scale),
"-n", model_name,
"-f", "png",
]
result_proc = subprocess.run(
cmd, capture_output=True, timeout=300
)
if result_proc.returncode != 0:
raise RuntimeError(
f"realesrgan-ncnn-vulkan failed: {result_proc.stderr.decode()}"
)
result = Image.open(out_path).convert("RGB")
# Resize to exact target if scale was non-integer
if result.width != target_w or result.height != target_h:
result = result.resize((target_w, target_h), Image.Resampling.LANCZOS)
return _to_png_bytes(result), "realesrgan_ncnn"
# ── Public entry point ────────────────────────────────────────────────────────
def upscale_sync(image: Image.Image, scale: float, method: str = "auto") -> tuple[bytes, str]:
"""
Upscale image synchronously. Call via run_in_executor from async context.
method values:
"auto" — pick best available automatically
"realesrgan_pytorch" — force PyTorch path
"realesrgan_ncnn" — force NCNN binary path
"lanczos" — force Lanczos
Returns (png_bytes, method_used_label).
"""
caps = probe_upscale_capabilities()
if method == "auto":
method = caps["recommended"]
if method == "realesrgan_pytorch":
if caps["realesrgan_pytorch"]:
try:
return upscale_realesrgan_pytorch(image, scale)
except Exception as e:
print(f"Real-ESRGAN PyTorch failed, falling back: {e}")
# Fall through to next best
if caps["realesrgan_ncnn"]:
try:
return upscale_realesrgan_ncnn(image, scale)
except Exception as e:
print(f"Real-ESRGAN NCNN fallback failed: {e}")
return upscale_lanczos(image, scale)
if method == "realesrgan_ncnn":
if caps["realesrgan_ncnn"]:
try:
return upscale_realesrgan_ncnn(image, scale)
except Exception as e:
print(f"Real-ESRGAN NCNN failed, falling back: {e}")
# Fall through
if caps["realesrgan_pytorch"]:
try:
return upscale_realesrgan_pytorch(image, scale)
except Exception as e:
print(f"Real-ESRGAN PyTorch fallback failed: {e}")
return upscale_lanczos(image, scale)
# Default / lanczos
return upscale_lanczos(image, scale)
async def upscale_image(image: Image.Image, scale: float, method: str = "auto") -> tuple[bytes, str]:
"""Async wrapper — runs upscale in thread pool to avoid blocking the event loop."""
loop = asyncio.get_event_loop()
return await loop.run_in_executor(None, upscale_sync, image, scale, method)