Step-by-Step BPGconv Tutorial: Convert, Optimize, and Serve BPG Images

Step-by-Step BPGconv Tutorial: Convert, Optimize, and Serve BPG Images

Overview

A concise guide to converting images to BPG (Better Portable Graphics) using BPGconv, optimizing file size/quality, and serving them on the web.

1. Install BPGconv and dependencies

• Linux/macOS: install libbpg tools or compile bpgenc/bpgdec from source.
• Windows: download prebuilt binaries or use WSL and follow Linux steps.

2. Convert images to BPG

• Basic command:

bpgenc input.png -o output.bpg

• Set quality (0–51, lower = better quality):

bpgenc -q 28 input.jpg -o output.bpg

• Preserve alpha (if supported):

bpgenc -a input.png -o output.bpg

3. Optimize size vs. quality

• Reduce quality for smaller files (try q=24–34 for web).
• Resize before encoding:

convert input.jpg -resize 1200x output-resized.jpgbpgenc -q 30 output-resized.jpg -o output.bpg

• Use chroma subsampling (4:2:0 default) to save more size: add -f 0 or consult encoder flags.

4. Batch processing

• Example shell loop:

for f in.jpg; do bpgenc -q 30 “\(f" -o "\){f%.*}.bpg”done

5. Convert back / preview

• Decode to PNG for preview:

bpgdec output.bpg -o preview.png

• Or use viewers that support BPG.

6. Serve on the web

• Use server-side detection to serve BPG to compatible browsers and fall back to WebP/PNG/JPEG for others.
• Example flow: check Accept header for “image/bpg” or use client-side feature-detection script. Serve .bpg when supported; otherwise, serve fallback image.

7. Automation & integration

• Add BPG conversion step to your image pipeline (CI, build scripts, or image CDN transform hooks).
• Generate multiple sizes and formats (BPG + WebP + JPEG) and use responsive or srcset logic.

8. Troubleshooting & tips

• If colors look off, check color profile handling and ensure sRGB conversion before encoding.
• Compare file sizes/quality against WebP and AVIF; test visually.
• Keep fallbacks for old browsers and platforms.

Quick example commands

bpgenc -q 28 -a input.png -o image.bpgbpgdec image.bpg -o image.png

If you want, I can provide platform-specific install commands, a ready-to-run batch script for your environment, or an HTML snippet to serve BPG with fallbacks.