Wikipedia:Reference desk/Archives/Computing/2020 June 12

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June 12

Silicon "Nipple"

On a laptop, you have a keyboard, under the keycap, there is a silicion "nipple", I am wondering what happens, if the "nipple" were to break, how hard would it be to type, and what damage would happen? --Thegooduser Life Begins With a Smile :) 🍁 00:20, 12 June 2020 (UTC)

See Keyboard technology#Dome-switch keyboard. Like most things in life, when dome switches break they tend to stop working. They do keep working with minor tears until the tear gets long enough that the dome falls off. --Guy Macon (talk) 04:35, 12 June 2020 (UTC)

Guy Macon Are these pretty strong? I hold down the shift key to type my passwords, and I am wondering if the silicon cup is strong? --Thegooduser Life Begins With a Smile :) 🍁 15:18, 12 June 2020 (UTC)

I have never heard of anyone ever damaging the rubber of a dome-switch laptop keyboard though heavy use, and I have set up many PCs on factory floors where they get a lot of abuse.

On any keyboard you can wear out the contacts, so whenever I buy an expensive laptop at the same time I buy a replacement keyboard and store it away in a cool, dry location. I have never needed the replacement, but then again whenever I use my laptop at home I use an external monitor and keyboard.

For use with a laptop I like the ViewSonic VA2452SM monitor[1] and the Ducky One keyboard with MX Blue keyswitches.[2][3]. --Guy Macon (talk) 18:37, 12 June 2020 (UTC)

Upscaled JPG images?

One of the notable things I have noticed from searching for digital images of historical paintings online is the fact that an image having more pixels does not mean that it has higher resolution, quality, and file size than another image of the same painting with lower amount of pixels and often times former have the same if not lower quality than the latter. This phenomenon is unfortunately quite common and as I am not an expert in digital images, I am going to guess this has something to do with quality losses involved in modification of JPG files also known as artefacts. In any case, I need help in determining if the following large images have higher quality or just the same compared to their their smaller counterparts:

1. Does this image has better quality and resolution than this one?
2. Does this image has better quality and resolution than this one?

In either case, after scaling the external image to the same size as the largest one on Wikimedia Commons using Preview with 600px/inch and image resampling, the result is considerably more blurry than the Commons image. I have not attempted to compare the 800 × 493 Alma-Tadema on Commons with the 2560 × 1576 Pinterest image.  --Lambiam 08:46, 12 June 2020 (UTC)

In general, when you scale an image to a smaller size (which is what happens when taking a photograph of a painting), detail gets lost. The smaller the size, the more detail is lost. Rescaling the smaller image to a larger scale will not restore any of the lost detail. When enlarging, a good rescaling algorithm will (almost) preserve the image quality. This applies in general for all digital image formats; it has nothing to do with jpeg artifacts. A problem with blowing up jpegs is that jpeg-specific compression artifacts may become visible and manifest as if the image consists of tiles. Many tools (e.g. Photoship) and online services can remove or at least mitigate these artifacts.  --Lambiam 09:00, 12 June 2020 (UTC)

• Question for OP Are the two JPEGs you talk about the same photo (taken from the same camera)? Bubba73 ^{You talkin' to me?} 00:00, 15 June 2020 (UTC)

I ask because photos of a piece of artwork may be from different sources. Before digital cameras were good, they scanned photographic prints. A high-resolution of a poor photograph will have a lot of pixels, but not be very good. Even within digital cameras, more pixels is not necessarily better - it depends on the sensor and the lens. Bubba73 ^{You talkin' to me?} 03:15, 15 June 2020 (UTC)

They were all found on the web, not identifying what camera they were made with.  --Lambiam 19:52, 15 June 2020 (UTC)

Then it is likely that they come from different sources that were executed in different ways. That could account for it. Bubba73 ^{You talkin' to me?} 20:00, 15 June 2020 (UTC)