MicroPython Forum (Archive)

What about screenshot of LCR160CR being saved to picture file (.jpeg, .png., etc) on internal flash or external flash (microSD) ? Has anybody implemented this feature ?

Maybe using the framebuffer, converting the frame buffer format to a picture format.

Yes, I know that the LCD160 module can show jpeg pictures.

See Note that buf holds pixels in RGB565 format.

chuckbook wrote: ↑

Wed Jan 03, 2018 9:27 am

See

Code: Select all

LCD160CR.screen_dump(buf, x=0, y=0, w=None, h=None)

Note that buf holds pixels in RGB565 format.

Thanks.
So the buffer could be saved to a binary file in RGB565 format.
Then I can copy the RGB565 files to a PC and use a PC tool (imagemagic, ffmpeg, etc) to convert the format to PNG, etc.

There's a bit more to it than that. A binary file provides no clues about the screen dimensions (in pixels). My approach would be to do as you suggest, but then to write a utility in Python to run on the PC to convert the file to a standard graphics format. Go for a simple uncompressed format like BMP.

Good idea to convert RGB565 to bmp.

I'll look at OpenMV MicroPython source code to try to get MicroPython code to save in BMP format (in the image module) :
http://docs.openmv.io/library/omv.image ... image.save
But I guess it is implemented in C/C++ :
https://github.com/openmv/openmv/tree/master/src/omv/py

It seems PPM image file format is simpler than BMP, easier to code even in MicroPython. For example :
PPM image from scratch in Python 3
nicholasRutherford/ppmFile.py
MANDELBROT FRACTAL IMAGE OUTPUT TO PPM FILE (PYTHON RECIPE)

Thanks for that - I'm sure that will come in handy. Converting to PPM looks very easy and Gimp can process the file.