image2cpp vs LCD Image Converter vs Online Tools 2026

There are a half-dozen tools for converting images into C/C++ byte arrays for embedded displays. Each has strengths. This post compares the five most popular options in 2026 — image2cpp, LCD Image Converter, the U8g2 bitmap tool, the LVGL online converter, and GIMP/ImageMagick scripts — and tells you which fits your workflow.

The five tools

image2cpp (pixel.hjlabs.in)

What it does well:

• Browser-based — no install, your image never uploads to a server
• Live preview as you tweak threshold, dither, or invert
• Multiple output formats: Adafruit-compatible MSB, XBM (LSB), vertical, RGB565, raw bytes
• Batch mode — drop multiple PNGs, get one array per file
• Floyd–Steinberg, Atkinson, and ordered dithering
• Mobile-friendly UI (works on tablets at hackathons)

Weaknesses:

• No 4-bit grayscale or indexed palette output (yet)
• No CLI for build pipelines
• Newer LVGL formats not directly supported — export raw bytes and wrap manually

Best for: Arduino, ESP32, RP2040, MicroPython projects targeting OLED, mono e-paper, or RGB565 TFTs. Try it now.

LCD Image Converter (riuson)

Desktop application with a powerful template system. Open source on GitHub.

What it does well:

• Custom output templates — generate any text format you need
• Font conversion (not just images) — great for custom display fonts
• Built-in editor for pixel-perfect tweaks
• Batch CLI mode for build pipelines

Weaknesses:

• Heavy GUI, slower iteration than a web tool
• Linux build is community-maintained, sometimes lags
• Steeper learning curve — the template language takes effort

Best for: Production firmware projects with build pipelines, custom font work, anything needing precise per-pixel control.

U8g2 bitmap tool

The U8g2 library author maintains both an online tool and a Python script for generating XBM data optimized for U8g2's drawing model.

What it does well:

• Native U8g2 vertical-byte format (no manual flag-flipping)
• Tightly integrated with U8g2 docs and examples
• Python CLI for build automation

Weaknesses:

• U8g2-specific outputs — awkward for Adafruit_GFX or LVGL targets
• No color support (U8g2 itself is mono-focused)
• Less polished UI than image2cpp

Best for: Pure U8g2 projects (small AVR with page-mode rendering).

LVGL online converter

The official tool at lvgl.io/tools/imageconverter. Generates ready-to-use lv_img_dsc_t declarations.

What it does well:

• Zero-config struct output for LVGL
• Supports all LVGL color formats (CF_TRUE_COLOR, CF_TRUE_COLOR_ALPHA, CF_INDEXED_8BIT, etc)
• Versioned for LVGL v8 and v9

Weaknesses:

• LVGL-only output — not portable
• No dithering controls
• No batch mode

Best for: LVGL-only projects. We covered the full integration in our ESP-IDF LVGL image conversion post.

GIMP / ImageMagick CLI

For build-system integration, ImageMagick can convert any image to XBM or raw bytes:

# Mono XBM
convert input.png -resize 128x64 -monochrome output.xbm

# RGB565 raw bytes (with custom script)
convert input.png -resize 320x240 -depth 8 input.rgb
python3 rgb_to_rgb565.py input.rgb > image_data.h

GIMP can export XBM directly: File → Export As → .xbm.

What it does well:

• Scriptable — runs in any CI pipeline
• Universal — you already have ImageMagick installed
• Reproducible — check scripts into git, never click a UI again

Weaknesses:

• No live preview — iterate by re-running and checking visually
• RGB565 conversion needs a custom script (5-10 lines of Python)
• Dithering options exist but are less tuned than image2cpp's

Best for: Production teams with mature build pipelines, consistent asset processing across hundreds of images.

Side-by-side feature matrix

Decision matrix by project type

The original javl/image2cpp vs pixel.hjlabs.in

The OG javl/image2cpp on GitHub is great but ad-supported and has been minimally maintained for years. pixel.hjlabs.in is a fork with:

• Refreshed UI (mobile-friendly, dark mode)
• Zero ads
• Additional output formats (Waveshare 3-color e-paper, LVGL raw bytes)
• Faster iteration (smaller bundle, instant load)
• Active maintenance and feature requests welcome

Both are 100% client-side — your image never uploads to a server.

Privacy as a feature

For commercial projects, "your image never leaves the browser" is a real advantage. Some teams cannot legally upload product imagery to third-party servers. image2cpp, LCD Image Converter, and GIMP all process locally. The LVGL online converter and many casual web tools upload to a server — check before using.

Bottom line

For 80% of hobby projects, image2cpp is the fastest path: drop in a PNG, tweak, copy. For LVGL projects, use the LVGL converter. For production firmware with strict build pipelines, scripts win. For custom fonts, LCD Image Converter is unmatched. Try image2cpp now — if it fits your workflow, you're done.

Other hjLabs.in tools: og.hjlabs.in for project README graphics, fmt.hjlabs.in for JSON, enhance.hjlabs.in if your source PNG needs upscaling, compliance.hjlabs.in for DPDPA privacy policies, and for laser-cut enclosures.