ESP32-EGA16-TGA

This is a ShittyCameraChallenge contribution to shoot 16-color (not 16-bit!) pictures on the ESP32-CAM.

There is a full write-up on the author's blog.

Example image:

Configuration

There is a bunch of #defines in the source to enable or disable various "features" of the project:

• WARMUP_PICS - number of pictures to discard while AWB is calibrating
• STORE_{RAW,RGB,TGA} - which file formats you want to end up on the SD card
• STORE_DITHER_* - which dither modes you want to store (see blog post)
• HEIGHT - you can set that to 240 to keep the 1:1 pixel aspect ratio. In theory, other resolutions might be possible if they match the pixel_format value.
• FORCE_8BPP_TGA - disable this to store a more compact but not supported by any modern viewer 4bpp packed TGA file

DO NOT TOUCH THE OTHER KNOBS!

Postprocessing for modern displays

To correct the non-square pixel aspect ratio and to better see the original pixels, it's recommended to upscale the image to 400%*480%, e.g. by using the following Makefile on the SD card:

TGA=$(patsubst %.tga, %.png, $(sort $(wildcard *.tga)))

all: $(TGA)

%.png: %.tga
	convert $< -scale 400%x480% $@

China Export Camera

This "feature" emulates a Nintendo GameBoy Camera. It can be toggled with the STORE_CHINA_EXPORT flag.

The RGB565 image taken will be downscaled to 128x112 (GBC output resolution), dithered to 4 greyscale colors, and put into the middle of a 160x144 image file.

For that, you need to generate ce_data.h by running python3 gen_ce_h.py - this script will expect a 160x144 PNG image under "china-export.png".