I'm really sorry you find this so frustrating. I had no idea that "GRAYSCALE", "RGB565" or any other of the formats need explanation.
- GRAYSCALE means values from 0 to 255 for each pixel
- RGB565 means that a 16 bit value is per pixel and is comprised from 5 bits red, 6 bits green and 5 bits blue.
- RGB888 means that there are 3 bytes per pixel, one for red, one for green and one for blue. Each vary between 0 and 255.
- YUV means that each pixel has it's Y channel as a separate byte (0 to 255) and each two adjacent pixels share their U and V values.
- JPEG means that the image is encoded into JPEG format either by the camera itself or in software.
When you get a frame from the camera, it will contain the frame buffer in the format you selected.
https://www.esp32.com/viewtopic.php?t=10405
https://github.com/espressif/esp32-camera/blob/master/conversions/include/esp_jpg_decode.h
https://www.youtube.com/watch?v=7qPIRBY6C8c&ab_channel=ThatProject
https://github.com/joachimBurket/esp32-opencv
docker pull espressif/idf:release-v4.2
cd esp32-opencv
docker run --rm -v $PWD:/project:z -w /project -it espressif/idf
./esp32/scripts/build_opencv_for_esp32.sh /opt/esp/idf/tools/cmake/toolchain-esp32.cmake /project/esp32/examples/ttgo_demo/main
cd esp32/examples/ttgo_demo
idf.py build