Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

A WiFi color eInk picture frame

spritesmods.com

Post reply on HN
Print view View original

41–50 of 89 posts

Re: A WiFi color eInk picture frame

#41

Post by crazygringo »

sho_hn wrote: post #37
crazygringo wrote: post #36

Earlier quoted context omitted.

For sure, my biggest question is if there are even any theoretical ideas about how to achieve it. Color is currently dark and so faded-looking, and even the "whites" are so muddy gray, because of the color filter technology. You can improve the number of intermediate color levels and improve the refresh rate, but the contrast and darkness is just an inherent limitation of putting color filters on top of what is other…

There are multi-pigment color e-ink displays that don't use a filter array. E-Ink's ACeP range uses four pigments (CMY+white). The white pigments are reflective, the others are transparent, and you basically sort of sort/stack them with different drive voltages, combining different pigments above white while leaving others below the white layer. I think OP is dissatisfied even with greyscale e-ink panels, though.

Oh wow, TIL. Thank you. Hadn't realized that was a new development. Just looked it up and the physics behind it sounds... extremely complicated.

Re: A WiFi color eInk picture frame

#42

Post by johnla »

c22 wrote: post #27
catapart wrote: post #3

Wow! There's a dynamite product in here that pairs a daily nagging app and one of these displays so that people are reminded to take a new picture, ever day, and have it show up on someone's (or all subscribed) photo frame. I'm thinking, like, "take a photo of the kids so it will show up on Grandma's frame" kind of functionality. Though, obviously, it would also be used for porn, so there's a market there, too. Anywa…

We don't have anything to nag us, but the grandparents and aunts and uncles all have Nixplay[0] frames that we regularly update with photos of the kids. [0] https://www.nixplay.com/

this won't be a popular suggestion but it works for us: We got the grandparents Nest Home Hub display. It's LCD and there's a switch to disable mic and camera but it works really well for photo sharing.

Re: A WiFi color eInk picture frame

#43

Post by SillyUsername »

This is the same e-ink device I believe that's in the Pimoroni Inky Impression.

I've written a Python program that anecdotally fixes the bias caused by the display for blues and greens, and dithers using an Atkinson dither. The code is based on some older Java implementation I wrote, but if you are considering a port to C this is more succinct (entry point diffuse_image()):

https://github.com/KodeMunkie/inky-impression-slideshow/blob...

The fix is to define the ink's blue as a slightly different hue than the device specifications, which tends to over emphasise it - improving it - when it comes to shades like sky blue (which the display can't achieve). So instead of (perhaps) being quantised to green, which is closer colour match for the actual real hue, more blue is shown instead. Whilst this is incorrect for photographic colour accuracy, if you don't know what the original photo looks like it appears to be correct and better than the colour that is typically chosen (green).

Re: A WiFi color eInk picture frame

#44

Post by adamckay »

squokko wrote: post #19

Don't see the advantage of eInk for a digital photo frame. Presumably these stay in one spot and can be left plugged in? Would think that a bright LED display would give much better picture quality.

But you can put them in places in your home where it's not practical or aesthetic to run cabling to plug them in (e.g. fireplace mantel or hung up on a wall) and have a battery life that is measured in weeks or months rather than days.

You'd be right about the superior picture quality, though, but as the common use would be family photos that you see in passing to make you smile and may be quick snaps, the quality of e-ink is likely to be enough when it's a quick photo of your loved ones.

Re: A WiFi color eInk picture frame

#45

Post by newhotelowner »

c22 wrote: post #27
catapart wrote: post #3

Wow! There's a dynamite product in here that pairs a daily nagging app and one of these displays so that people are reminded to take a new picture, ever day, and have it show up on someone's (or all subscribed) photo frame. I'm thinking, like, "take a photo of the kids so it will show up on Grandma's frame" kind of functionality. Though, obviously, it would also be used for porn, so there's a market there, too. Anywa…

We don't have anything to nag us, but the grandparents and aunts and uncles all have Nixplay[0] frames that we regularly update with photos of the kids. [0] https://www.nixplay.com/

I bought one for India. My parents don't have a wifi but they have a smart phone with a data plan. Hoping they will be able to enable access point on their phone to sync photos.

Re: A WiFi color eInk picture frame

#47

Post by sho_hn »

SillyUsername wrote: post #43

This is the same e-ink device I believe that's in the Pimoroni Inky Impression. I've written a Python program that anecdotally fixes the bias caused by the display for blues and greens, and dithers using an Atkinson dither. The code is based on some older Java implementation I wrote, but if you are considering a port to C this is more succinct (entry point diffuse_image()): https://github.com/KodeMunkie/inky-impressi…

Thanks for sharing! Atkinson dithering is a great choice for these panels. What the result lacks in detail it gains in contrast, and since e-ink panels don't have the greatest contrast ratios it's a good match.

Sierra dithering is a nice compromise between Atkinson and basic Floyd-Steinberg.

Re: A WiFi color eInk picture frame

#48

Post by jamiek88 »

konschubert wrote: post #33
catapart wrote: post #3

Wow! There's a dynamite product in here that pairs a daily nagging app and one of these displays so that people are reminded to take a new picture, ever day, and have it show up on someone's (or all subscribed) photo frame. I'm thinking, like, "take a photo of the kids so it will show up on Grandma's frame" kind of functionality. Though, obviously, it would also be used for porn, so there's a market there, too. Anywa…

This display offers a simple API to build applications for it: https://shop.invisible-computers.com/products/invisible-cale... https://github.com/Invisible-Computers/image-gallery/blob/ma... It's black-and-white, but dithering allows to show surprising detail and it brings its very own old-school aesthetic. The API doesn't require any special knowledge about e-paper displays, it just expects an image URL in the corre…

Is this for sale still? It shows sold out on the site.

Re: A WiFi color eInk picture frame

#49

Post by SillyUsername »

SillyUsername wrote: post #43

This is the same e-ink device I believe that's in the Pimoroni Inky Impression. I've written a Python program that anecdotally fixes the bias caused by the display for blues and greens, and dithers using an Atkinson dither. The code is based on some older Java implementation I wrote, but if you are considering a port to C this is more succinct (entry point diffuse_image()): https://github.com/KodeMunkie/inky-impressi…

I've not run the code in a while but you can find a screenshot here: https://user-images.githubusercontent.com/13253888/166610362... (nb. isn't of actual display, but gives you an idea of quality)

and a bit of discussion early on about the colour issues: https://github.com/pimoroni/inky/issues/115

Re: A WiFi color eInk picture frame

#50

Post by leipert »

konschubert wrote: post #20
notfried wrote: post #8

Or you can buy Soldered's: https://soldered.com/product/inkplate-6color-with-enclosure-...

Or this one, which has less of a hacker aesthetic. https://shop.invisible-computers.com/products/invisible-cale... It also comes with software out of the box

You could at least disclaim that you are the CEO, at least on your HN profile.

https://www.invisible-computers.com/imprint.html

Post reply on HN