Install

# macOS
brew install --cask upscayl

# Or download from upscayl.org

CLI Usage

upscayl-cli -i input.png -o output.png -s 4 -m realesrgan-x4plus

Models

realesrgan-x4plus: General purpose
realesrgan-x4plus-anime: Anime/illustrations
ultramix_balanced: Balanced quality
ultrasharp: Maximum sharpness

Real-ESRGAN (Python)

Install

pip install realesrgan

Usage

from realesrgan import RealESRGAN
from PIL import Image

model = RealESRGAN('cuda')  # or 'cpu'
model.load_weights('weights/RealESRGAN_x4plus.pth')

image = Image.open('input.png')
upscaled = model.predict(image)
upscaled.save('output.png')

CLI

realesrgan-ncnn-vulkan -i input.png -o output.png -s 4

Magnific AI (Creative)

Best for creative enhancement, not just upscaling.

Features

Resolution increase up to 16x
Creative hallucination (adds detail)
Style control
Face enhancement

API

import requests

response = requests.post(
    "https://api.magnific.ai/v1/upscale",
    headers={"Authorization": f"Bearer {API_KEY}"},
    json={
        "image_url": "https://example.com/image.jpg",
        "scale": 4,
        "creativity": 0.5,  # 0-1, higher = more AI enhancement
        "style": "photo"    # photo, art, anime
    }
)

Use Cases for App Development

App Store Screenshots

# Upscale 1x to 3x for retina displays
upscayl-cli -i screenshot.png -o screenshot@3x.png -s 3

Icon Generation

# From 256px to 1024px for App Store
upscayl-cli -i icon_256.png -o icon_1024.png -s 4

Marketing Assets

# Upscale for print/billboard
upscayl-cli -i hero.png -o hero_print.png -s 8

Batch Processing

Script

#!/bin/bash
for file in input/*.png; do
    filename=$(basename "$file")
    upscayl-cli -i "$file" -o "output/${filename%.png}_4x.png" -s 4
done

Python

from pathlib import Path
from realesrgan import RealESRGAN
from PIL import Image

model = RealESRGAN('cuda')
model.load_weights('weights/RealESRGAN_x4plus.pth')

for path in Path('input').glob('*.png'):
    image = Image.open(path)
    upscaled = model.predict(image)
    upscaled.save(f'output/{path.stem}_4x.png')

Quality Tips

Best Results

Start with highest quality source
Remove compression artifacts first
Use appropriate model for content type
Don't upscale more than 4x per pass

Multiple Passes

# For extreme upscaling, do 2 passes
upscayl-cli -i input.png -o temp.png -s 4
upscayl-cli -i temp.png -o output.png -s 4
# Total: 16x upscale

Face Enhancement

# Use GFPGAN for face restoration
pip install gfpgan
gfpgan -i face.png -o restored.png --upscale 4

Comparison by Content

Content	Recommended Tool
Photos	Topaz or Real-ESRGAN
Anime/Art	Waifu2x or Real-ESRGAN-anime
Faces	GFPGAN
Text/UI	Lanczos (no AI)
Creative	Magnific

Use when: App Store assets, marketing images, icon generation, photo restoration

Tool	Best For	Free Tier	Pricing
Topaz Gigapixel	Photos	Trial	$99 one-time
Real-ESRGAN	Open source	Unlimited	Free
Magnific AI	Creative upscale	10 images	$39/mo
Let's Enhance	Easy web tool	10 images	$12/mo
Upscayl	Local, free	Unlimited	Free

Upscale Expert

Upscale Expert

Tools Comparison

Upscayl (Free, Local)