E-Paper Floyd-Steinberg

Introduction

• Floyd-Steinberg dithering algorithm is very suitable for showing rich layering when color is less. More color combinations for better shadow rendering of the original image. It is especially suitable for various usage scenarios of e-ink screens.
• The following will introduce how to convert ordinary pictures into Floyd-Steinberg scatter plots.
• If you are interested in the actual algorithm, you can read about our algorithm porting on ESP32 link hereand ESP8266 link here

Operating Steps

Preparation: Download color table to PC, and unzip to get the file as shown below, we are going to use "N-color.act." or "4-color.act".

1. Create a Photoshop project, set the width and height according to the actual resolution of the e-Paper screen, the color mode uses RGB color. Here we use 7.5inch e-Paper 800*480 as an example for demonstration. If you are using a screen of other sizes, you can modify the corresponding resolution.

2. Prepare the corresponding picture, copy it into the project, and adjust the parameters such as size and contrast (similar to the steps for processing pictures in general Photoshop).

3. Select File->Save for Web and Devices.

4. Select the color table as shown below. Load the color table provided in Preparation.



5. For black and white pictures, load Black-White.act, then click Save and save as a gif file. For different applications, it can be converted to JPG or BMP and other image formats later.

6. Other color tables, display effects as shown below:
Black-White-Red.act--corresponding to Black, White and Red, three-color e-Paper screen.

Black-White-Yellow.act--corresponding to Black, White and Yellow, three-color e-Paper screen.

N-color.act---corresponding to Black and White, Red, Green, Blue, Yellow and Orange, seven-color e-Paper screen.

Picture Format Conversion Steps

The default exported image format is GIF, and in most cases we need to convert it to another format.
Note: The following methods all use the system default tools, if there is not your desired format, please install a third-party software for conversion.

Windows

Use the drawing software "Paint" to open the picture, click "File" -> "save as".

MAC

Use the system's built-in viewing tool to open the picture, click "File" -> "Export".


Then enter the format you want to convert from GIF.