Why we love Galaxy S7’s lower-res camera .


Here’s why megapixels don’t matter on your smartphone camera

Galaxy S7 camera back samsung

In technology as in life, bigger is usually better. The iPhone 6s Plus’s main selling point is that its screen is nearly an inch larger than the iPhone 6s. A terabyte hard drive is obviously better than a gigabyte hard drive. No one advertises that their headphones are quieter than the competition’s.

But cameras are hard to measure in terms of size.

We denote aperture, the most important spec on a smartphone camera, in weird numbers like f/2.2 and f/1.7 — and f/1.7 is actually the better of the two! And even that is only true in some circumstances! The only element of photography where bigger really is better is sensor size, and that hits a hard upper limit in the cramped confines of a thin pocket device.

So tech reviewers without backgrounds in photography zero in on a spec that seems to matter, but really doesn’t: megapixels.

Megapixels are a measure of resolution, or the number of individual dots packed onto a camera’s sensor. A one-megapixel image has 1 million pixels. If it’s perfectly square, that means it’ll have 1,000 pixels on each side. That’s about the size of a typical image on a website. If you’re reading this on an HD screen, you’re seeing a smidge more that 2 megapixels. A 4k screen has over 8 megapixels. In order to print an image across the glossy pages of National Geographic you’ll want about 10.

You can see then that megapixels do matter up to a point. But every major smartphone brand on the market shot past that point years ago. Still, it’s the only measure of a camera most people have heard of or understand. Which is how you end up with statements like this one from CNET’s review of the Galaxy S7:

“Although this camera has fewer megapixels than last year’s S6, it takes better photos. Scenes are brighter, which makes the action easier to see.”

The Galaxy S6 had a 16 megapixel camera. The S7 has 12 megapixels. A reasonable person might assume that would be a disadvantage, but in reality it’s an advantage. Let’s explore why.

First, megapixel counts on their own have no impact on optics — that’s all to do with the lens. Check out these two images:

megapixels qualityRafi Letzter/Tech Insider

I shot both using the same lens, but with different cameras. The one on the left comes from a 12 megapixel Nikon D700, the one on the right from a 36 megapixel Nikon D800. There’s no difference in sharpness, color quality, sensor size, aperture, or any other optical effect. The only advantage the D800 has over the D700 is that it’ll print magazine-quality images up to the size of my wall, rather than just a large poster. Great for counting pores, but otherwise useless.

(And no, digital zoom doesn’t count as a good use if you care about image quality — which, if you’re reading this article, I assume you do.)

But high megapixel counts are more than just useless in most circumstances. They can actually be harmful to image quality. The more dots you pack into the tiny area of a smartphone camera sensor, the smaller they have to be. And the smaller they are, the weaker they’ll be at accurately detecting light brightness and color.

i tried again under a softer light in a different part of the store but ran into the same problem again the iphone had no trouble in this situationRafi Letzter/Tech Insider

A great example of a smartphone that chased megapixel counts off a quality cliff is the Sony Xperia Z5. Packing and proudly advertising a whopping 23 megapixels — more than Nikon’s $6,500 D5 camera — Sony promised a “revolutionary” device. But my comparison revealed a machine that fell well short of the mark. Highlights got blown out, shadows clipped, and the image was actually less sharp than the 12 megapixel iPhone 6s Plus due to imperfections in the lens.

Finally, super-duper-high-res images are just a drag on your storage capacity. The 12 megapixel Galaxy S7 shoots images that hover around 3 megabytes. The 16 megapixel phones make images that nearly double that at 7 or 8 megabytes. That means that a small sacrifice in print size can lead to more than double the photo storage capacity on the same sized card.

Samsung and Apple seem to have found the smartphone sweet spot at 12 megapixels — big enough for beautiful prints, but small enough to retain quality and storage space. Instead focusing on engineering problems like lensing empowers those companies to make the best smartphone cameras on the planet. Expect megapixel counts on other brands’ devices to drop as they fight to keep up.

Amputee Regains Sense Of Touch With Bionic Fingertip, Subsequently Feels Different Textures


Bionic fingertip

A property developer in Denmark thought he lost his sense of touch for good after a fireworks accident forced doctors to amputate his left hand. Nine years later, in what is a scientific breakthrough, Dennis Aabo Sorenson can now feel different textures beneath his fingertips. Yesterday, a team of Swiss and Italian researchers were able to bring back Sorensen’s ability to feel with a bionic fingertip — without surgery.

Sorenson’s sense of touch was restored with the help of a bionic finger. At 36, he is the first amputee to try the bionic fingertip that allows him to touch and feel different textures on his left hand.

“The stimulation felt almost like what I would feel with my hand,” said Sørensen about the artificial fingertip connected to his stump of a wrist, in a statement. He added: “I still feel my missing hand, it is always clenched in a fist. I felt the texture sensations at the tip of the index finger of my phantom hand.”

Researchers Silvestro Micera and his team at the École Polytechnique Fédérale de Lausanne in Switzerland created the silicon bionic finger using electromechanical sensors that gain sensory data from a surface. The electronic signals were then converted by computer into nerve signals simulated to function as those that occur when running a finger across different textures.

In the experiment, Sørensen’s arm was wired to an artificial fingertip equipped with sensors. Micera’s team hooked the bionic finger up to a machine that moved it over different pieces of plastic engraved with smooth or rough textures. The fingers were also connected to electrodes that were implanted in the amputee’s upper arm.

When Sørensen’s finger moved, he experienced the sensation of texture where the index finger of his amputated arm had been. He could distinguish between surfaces 96 percent of the time.

“It was very close to the feeling in my real arm — you can feel coarseness and the different gaps and ridges,” he said.

Sorenson actually sensed textures better than four non-amputees on whom the same experiment was conducted. Researchers inserted a single electrode — like an acupuncture needle — into their upper arms. The non-amputees were able to distinguish roughness in textures 77 percent of the time. In addition, Micera’s team compared the brain-wave activity of the non-amputees, once with the artificial fingertip and then with their own finger, to assess how accurately it mimicked human touch. The brain waves collected by an EEG cap revealed the sensations indeed resemble those felt naturally by the human hand.

“The brainwaves were similar in both experiments,” said study author Calogero Oddo, from the Biorobotics Institute in Pisa, Italy.

A similar 2014 study gave amputees the sense of touch and pressure. Two amputees had electrodes implanted into their upper arms, which allowed them to generate unique impulses to sense fine touch, firm touch, and pressure. The amputees were able to complete difficult routine tasks, such as plucking the stem from a cherry when they could feel. Moreover, they claimed the implant eliminated the feeling of a “phantom hand,” or pain, because the brain interpreted the hand still being there. This technology could be available within five to 10 years.

Meanwhile, the development of the bionic finger holds promise for allowing amputees to feel fine textures. Micera and his colleagues are now working toward allowing amputees to feel natural stimuli, such as jeans.

The idea is to eventually combine the fingertip sensors within a full prosthesis that would allow amputees worldwide to grip and feel objects, with no surgery required.

Source: Oddo CM, Raspopovic S, Artoni F et al. Intraneural stimulation elicits discrimination of textural features by artificial fingertip in intact and amputee humans.

Watch the video. URL:https://youtu.be/8l20OCaQV1s

GN-z11


https://en.wikipedia.org/wiki/GN-z11?_e_pi_=7%2CPAGE_ID10%2C3429364897

Allergic food prevention.


In a general population of breast-fed infants, introducing allergenic foods at age 3 months versus after 6 months did not significantly reduce risk.

Based on positive findings for prevention of peanut allergy with early peanut introduction in children with high risk for allergy (NEJM JW Pediatr Adolesc Med Apr 2015 and N Engl J Med 2015; 372:803 and NEJM JW Pediatr Adolesc Med Mar 4 2016; [e-pub] and N Engl J Med 2016 Mar 4; [e-pub]), U.K. researchers examined whether early introduction of other allergenic foods in a general population of infants might also be protective.

Investigators randomized 1300 exclusively breast-fed infants to introduction of allergenic foods (milk [first], peanut, egg, sesame, fish, and wheat [last]) either at 3 or after 6 months of age. Parents reported consumption data via online questionnaire, and peanut-protein levels were measured from bed dust at 3 and 12 months to assess adherence. The primary outcome was allergy to ≥1 food between ages 1 and 3 years.

In an intention-to-treat analysis, early introduction was associated with a nonsignificantly reduced risk for allergy compared with later introduction (5.6% vs. 7.1%). In a per-protocol analysis, early introduction was associated with significantly reduced risks for allergy to any food (2.4% vs. 7.3%), peanut (0% vs. 2.5%), and egg (1.4% vs. 5.5%), but the differences were nonsignificant when nonadherent families were included. Adherence was substantially lower in the early introduction group (43% vs. 93%).

COMMENT

  1. David J. Amrol, MD

Introducing solid foods to infants is difficult, as reflected in the low adherence in this study, but families that did adhere to the diet saw a reduction in allergy risk. It is too early to say if this early food introduction strategy works (as the per-protocol results could be due to reverse causation), and implementation is definitely difficult. However, we can conclude that early peanut introduction in atopic children is protective, and that the introduction of other allergenic foods does not lead to food allergy and may be helpful if sufficient amounts can be consumed. I will tell parents to breast-feed for 3 months and then start introducing all foods (being mindful of aspiration), and to introduce allergenic foods as early as possible, but not at the cost of feeding battles or sleep loss if their baby is not ready to consume them regularly.

– See more at: http://www.jwatch.org/na40714/2016/03/08/does-early-introduction-allergenic-foods-prevent-childhood?ijkey=PGviq5SENtda6&keytype=ref&siteid=jwatch&variant=full-text#sthash.NhBbX5KW.dpuf

Pseudotumoral presentation of cerebral amyloid angiopathy–related inflammation


Objective: To identify the clinical and radiologic features that should raise suspicion for the pseudotumoral presentation of cerebral amyloid angiopathy–related inflammation (CAA-I).

Methods: We retrospectively reviewed the characteristics of 5 newly diagnosed and 23 previously reported patients in whom the CAA-I imaging findings were initially interpreted as CNS neoplasms.

Results: Most cases (85%) occurred in patients >60 years old. The clinical characteristics at presentation included subacute cognitive decline (50%), confusion (32%), focal deficits (32%), seizures (25%), and headaches (21%). Brain MRI demonstrated infiltrative white matter lesions that exhibited a loco-regional mass effect without parenchymal enhancement (93%). In general, these findings were interpreted as low-grade glioma or lymphoma. Eighteen patients (64%) underwent a biopsy, which was nondiagnostic in 4 patients (14%), and 6 patients (21%) underwent a surgical resection. The primary reason for the misinterpretation of the imaging findings was the absence of T2*-weighted gradient recalled echo (T2*-GRE) sequences on initial imaging (89%). When subsequently performed (39%), the T2*-GRE sequences demonstrated multiple characteristic cortical and subcortical microhemorrhages in all cases. Perfusion MRI and magnetic resonance spectroscopy (MRS), which were performed on a subset of patients, indicated markedly reduced relative cerebral blood flow and a normal metabolic ratio.

Conclusion: The identification of one or several nonenhancing space-occupying lesions, especially in elderly patients presenting with cognitive impairment, should raise suspicion for the pseudotumoral presentation of CAA-I and lead to T2*-GRE sequences. Perfusion MRI and MRS appear to be useful techniques for the differential diagnosis of this entity.