TM4C123GH6PM: Display PNG pictures on E-INK display

You do not "make the case" for "PNG & only PNG" - is that not true?      (and E-INK's choice - equally silent)    Note that the accommodation of color vastly expands your, "harvest of existing or new images" which likely is curtailed by the selection of  "mono/shades of gray" display.      Indeed E-INK is "sunlight readable" and low power - yet converting "normal" color images (usually) provides high challenge...

While PNG is a compressed file - so too is JPG - and Cortex M4 & M7 MCUs exist with HW "engines" which, "Speed, Ease, Enhance" the display of such JPG images.     It is hoped that "one-day" such capability "arrives here" - yet is alive/well elsewhere - and may even include superior, Graphic accommodation of more powerful displays - and their newer/demanding interfaces...

Jan Juranek said:

Do you think that Tiva ARM has enough power to decode PNG pictures?

Jan Juranek said:

Or I have to find another compression method?

E.g. looking at an example 1920 x 1160 image:

a) A .bmp file with 24-bit colour depth was 6,681,654 bytes.

b) A .png file with 24-bit colour depth was 133,201 bytes.

c) The compressed output from the pnmtoc tool with a 256 colour palette index created an array of 350,631 bytes which is an image array in the format used by the TivaWare grlib.

d) The compressed output from the pnmtoc tool with a 1 bit colour palette index (i.e. black and white) created an array of 64,430 bytes which is an image array in the format used by the TivaWare grlib.

Therefore, the compressed output from the TivaWare pnmtoc tool might provide sufficient compression for your application. The amount of compression will vary with the image.

Also, what is the colour depth of the E-INK display?

Chester Gillon said:

Also, what is the color depth of the E-INK display?

Unless recently developed & introduced - E-Ink is confined to, "Mono and shades of gray."     (if this holds true today - as earlier stated - poster's image selection & processing is (likely) made far more labor & time intensive - and complex.)

The choice of an MCU w/ "in-built" HW JPG capability - vastly faster System Clock - and accommodation of the "latest/greatest" display interface standards - appears (alone) to meet poster's desire for "best choice."

Thank you for replies!

Chester Gillon said:

Also, what is the colour depth of the E-INK display?

Well, it depends. For example E-INK display from Good-display.com (13.3 inch, 1600x1200) can display images at 2-16 (1-4bits) gray levels.

I'd like to use it as "electronic song-book" (I'm guitarist). We already have 10 inch e-reader, but it has got several disadvanteges for us, so I'd like to develop my own solution. For example I can get monochromatic scan from my scanner so I can make monochrome PNG images. I think that I will start with BMP pictures. I know they are big, but for first tests it's simple and I will check more powerful ARMs with HW accelaration.

NetPNM Converter looks interesting, I will check it!!

Jan