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Ubify Media & Design Operations
UI/UX & DIGITAL MEDIA SPECIALISTS
About This Tool
Reflective electrophoretic e-Paper displays operate with fixed micro-encapsulated pigment particles (such as 7-color Waveshare ACeP or 3-color red/yellow displays) and cannot natively render continuous 24-bit RGB photographic gradients.
This utility converts full-color images into discrete e-Paper palettes using spatial error-diffusion dithering algorithms (Floyd-Steinberg and Atkinson) or direct nearest-neighbor thresholding. It quantizes each pixel to the nearest physical pigment (Black, White, Green, Blue, Red, Yellow, and Orange for 7-color displays, or Black, White, and Red/Yellow for 3-color panels) and exports a ready-to-compile Arduino and ESP32 C code array formatted for GxEPD2 and Waveshare microcontroller libraries.
For example, uploading a landscape photo with the Waveshare Spectra 7 palette and Floyd-Steinberg dithering maps intermediate color tones into dot patterns of the seven physical pigments and outputs a C hex array you can paste directly into your firmware sketch.
All image quantization and C array generation executes client-side on an HTML5 canvas inside your web browser. Uploaded artwork and source photos never leave your device.
How to Use
- 1
Upload or drag and drop your image file (PNG, JPEG, or WebP).
- 2
Select your target e-Paper hardware palette (Waveshare 7-Color Spectra 7, 3-Color BWR, or 3-Color BWY).
- 3
Choose your dithering algorithm (Floyd-Steinberg error diffusion, Atkinson diffusion, or nearest color threshold).
- 4
Adjust the image contrast slider to tune shadow separation and highlight punch.
- 5
Inspect the canvas preview and copy the generated PROGMEM C byte array for your microcontroller firmware.
Frequently Asked Questions
What seven colors are available in the Spectra 7 / ACeP palette?
The palette contains seven discrete physical electrophoretic pigments: Black, White, Green, Blue, Red, Yellow, and Orange.
What is the difference between Floyd-Steinberg and Atkinson dithering?
Floyd-Steinberg diffuses 100% of quantization error to adjacent pixels for smooth gradients, whereas Atkinson diffuses only 75%, preserving crisp edges and higher local contrast on low-resolution reflective screens.
Are my image uploads sent to a cloud server?
No. All canvas dithering and array serialization runs locally in your browser.