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See what’s new in Firefox 56.0 Release !

See what’s new in Firefox 56.0 Release !

See what’s new in Firefox!

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.


Firefox Release

September 28, 2017

Version 56.0, first offered to Release channel users on September 28, 2017

Today’s release gives Firefox users a better experience with features like Firefox Screenshots, Send Tabs, and more control over the browser with an improved (and searchable) preferences section. It also includes incremental performance improvements that move us closer to our biggest release of the year, coming in November.

We’d like to extend a special thank you to all of the new Mozillianswho contributed to this release of Firefox!


  • Launched Firefox Screenshots, a feature that lets users take, save, and share screenshots without leaving the browser
  • Added support for address form autofill (en-US only)
  • Updated Preferences
    • Added search tool so users can find a specific setting quickly
    • Reorganized preferences so users can more easily scan settings
    • Rewrote descriptions so users can better understand choices and how they affect browsing
    • Revised data collection choices so they align with updated Privacy Notice and data collection strategy
  • Media opened in a background tab will not play until the tab is selected
  • Improved Send Tabs feature of Sync for iOS and Android, and Send Tabs can be discovered even by users without a Firefox Account



  • Replaced character encoding converters with a new Encoding Standard-compliant implementation written in Rust
  • Added hardware acceleration for AES-GCM
  • Updated the Safe Browsing protocol to version 4
  • Reduced update download file size by approximately 20 percent
  • Improved security for verifying update downloads


Developer Information


  • Startup crash with RelevantKnowledge adware installed. Firefox Support has helpful instructions to remove it.
  • Startup crashes with 64-bit Firefox on Windows 7, for users of Lenovo’s “OneKey Theater” software for IdeaPad laptops. To fix this crash, please re-install 32-bit Firefox.
  • Users running Firefox for Windows over a Remote Desktop Connection (RDP) may find that audio playback is disabled due to increased security restrictions. Learn how to mitigate this issue until it is corrected in an upcoming release.
  • Due to a bug in Mac OS X High Sierra, fullscreen mode has some issues


(来自Mozilla CEO的祝福)

体验崭新的 Firefox:快,只为更好!

今天,我们很高兴地向大家介绍全新的 Firefox 浏览器——Firefox Quantum。

首先,您肯定会注意到,全新的 Firefox 有着风驰电掣般的速度。在实际体验中,您感受到的速度比一年前的版本快一倍。与此同时,它的性能也更加强大。我们专注于探索用户如何利用互联网无拘无束地观看、收听、创作和娱乐,于是着手重新打造了 Firefox。我们很高兴能为大家提供这样一个有着全新体验的浏览器——现代、快速、高效。相信您也一定深有同感:这将是您未来互联网体验中的一大飞跃。

在您使用 Firefox 时,您也在为我们保护互联网为一项开放的、人人可用的全球公共资源作出贡献。作为一个独立的非营利组织,Mozilla 自 2003 年以来便一直致力于打造由用户自己控制在线生活的产品,并持续推动开放技术和公共政策,促进互联网健康发展。我们始终以您为本!

今天,我谨代表 Mozilla 全球社区,非常自豪地向您介绍崭新的 Firefox。快,只为更好!

Chris Beard
Mozilla 首席执行官


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100,434 views judgement/review in judgement/review in

Today (Jan.27th), when I surf on the internet, I occasionally find some information about the current status of the blog.

My surfing link is – .

In the second record in the first search result page, the is showed as below:

3fcode.comMr.SirBlog – 让自己不一样 is tracked by us since August, 2017. Over the time it has been ranked as high as 1 897 499 in the world. All this time it was owned by Vvv Jia …

I was a little surprised , as I didn’t expect some other website had collected and judged my blog.

After reading the detail information the easycounter site gives, I should say, it’s kind of fair, and described a good brief info.

Here I want to say one by one:

Rank info:

Global rank 1 897 499
Daily visitors 1.04K
Daily pageviews 1.04K
Pageviews per user 1
Rating  1 Star –
Status Online
Latest check

Countable Data Brief is tracked by us since August, 2017. Over the time it has been ranked as high as 1 897 499 in the world. All this time it was owned by Vvv Jia, it was hosted by LLC.

3fcode has the lowest Google pagerank and bad results in terms of Yandex topical citation index. We found that is poorly ‘socialized’ in respect to any social network. According to Google safe browsing analytics, is quite a safe domain with no visitor reviews.

Worldwide Audience

It seems that traffic on this site is too low to be displayed, sorry.

Traffic Analysis has 1.04K visitors and 1.04K pageviews daily.


 Subdomains Traffic Shares has no subdomains with considerable traffic.

SEO Stats is not yet effective in its SEO tactics: it has Google PR 0. It may also be penalized or lacking valuable inbound links.


Domain Registration Data domain is owned by Vvv Jia and its registration expires in 2 months.


GeneralGet more whois history

Vvv Jia

Owner since August 03, 2017

2 months left

Expires on April 16, 2018

9 months old

Created on April 16, 2017

9 months ago

Changed at April 16, 2017

Registrar and Status

Status clientDeleteProhibited




In Other TLDs

No data

Social Engagement

It seems has no mentions in social networks.

Server Information uses WordPress CMS and is hosted by, LLC.

IP WhoisGet more server history

  •, LLC
  • 166.62.30.xxxIP address

Server Technologies

  • Apache HTTP ServerBackend server
  • WordPressCMS


Safety status of is described as follows: Google Safe Browsing reports its status as safe.

Get more reviews

Other info


Overall reputation Unknown
Trustworthiness Unknown
Privacy Unknown
Child safety Unknown

Google Safe Browsing

Website status Safe
Status ok

User reviews

Reputation Unknown review given by

To create 3 Fcode review we checked reputation at lots of sites, including Siteadvisor and MyWOT. Unfortunately, we did not find sufficient information whether 3fcode is safe for children or does not look fraudulent. We would describe it as legit.

Vvv Jia still needs more reviews of their project as there is too little data to define the site’s trustworthiness. Please be warned that to describe security status of we use data openly available on the Web, thus we cannot guarantee that no scam sites might have been mistakenly considered legit and no fraud or PC issues may occur in this regard. But usually the crowdsourced data we have is pretty accurate. Let’s see it below.



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The 100 essential websites

The 100 essential websites

Here we go again … our latest list of the 100 best websites sees short attention spans, the rise of Twitter, more browser wars and celebrity gossip sites setting the news agenda

Andy Warhol talked of a time when everyone would be famous for 15 minutes. With hindsight, however, he might have wanted to revise that down to about five minutes. On today’s web, phrases such as “here today, gone tomorrow” seem to involve ridiculously long timescales.

People who moaned that blogging represented a move to shorter attention spans – 250-to-350-word posts rather than 1,000-word stories – have now seen blog posts start to look big and, frankly, old-fashioned. Today’s trendsetters are using “microblogging” sites such as TumblrPosterous and, which are taking the opportunity for creative “borrowing” to new heights.

But the smash hit of 2009 has been (apologies: I know this will cause pain) Twitter, where 1,000-word stories are reduced to 140-character tweets. Short attention spans R us.

Twitter’s rapid growth and open programming interface have given the site a wide impact. Hundreds, possibly thousands, of ancillary sites and services have been launched to help Twitter users post pictures, track followers, or – more usefully, from a commercial point of view – find out what the “hive mind” is thinking. Twitterfall is just one example. More recently, Listorious stepped in to make it easier to find and explore lists made using Twitter’s new list feature, while The Twitter cleverly turned selected tweets into a personalised newspaper. How many of these sites will survive is, of course, open to question. Some are less like standalone sites than parasites.

Major web players such as Facebook, Google, and Microsoft also got involved. Both Google and Microsoft signed deals for Twitter searches, while Facebook paid it the ultimate compliment of more or less copying its service. Or, perhaps, copying FriendFeed, which many users link to both Twitter and Facebook.

Facebook, while far from new, was another big player in 2009, reaching more than 350 million users. And through Facebook Connect, it has extended its presence across the web. Once you have a Facebook identity – and you must have one, mustn’t you? – then you can use it to access a growing number of sites and services. And that’s not necessarily a bad thing. The web might be a kinder, more polite place if people said things under their real names, which is what Facebook’s about.

Those in search of their five minutes of fame or, more likely, five minutes of fun fun fun, headed for YouTube. Although it has been challenged by rivals such as Vimeo and Microsoft’s Soapbox (RIP), its dominance has not been seriously threatened. Only the pornographers have been able to build much of a following outside YouTube.

Which is not to say that YouTube owns the web video market. The BBC has made a huge impact with its iPlayer catchup service, and in the US, Hulu has enjoyed great success with TV series and movies. Of course, both sites are showing videos that YouTube would love to offer, at a profit, and it will be interesting to see how this plays out.

Music has been a significant player in the growth of the web since Napster, and its influence continues to grow. Spotify has made the biggest impact this year, gaining mindshare lost by and Pandora. Meanwhile, Pitchfork has expanded its role as the web’s authoritative music magazine, and The Hype Machine came to prominence as a source of instant erudition by tracking the music blogs.

Almost finally, it may be that we are seeing the return not just of the browser wars but of the search engine wars as well. Google still rules the world, but in Bing, it now has a competitor that does some things better and has, in Microsoft, an owner with deep pockets. Alas, Bing also does many things a lot worse.

Possibly the most contentious part of this year’s list is celebrity gossip. The argument against would be summed up by a Wikipedian in two words: “not notable”. The argument for is that sites such as Perez Hilton and AOL’s TMZ are now helping to drive the news agenda. Even if you aren’t interested in Michael Jackson’s death, Tiger Woods’s affairs or whatever, this stuff has become impossible to avoid. This is one case where many people would prefer the web’s short attention span to be even shorter.


Now easier than falling off a log.

Tumblr Multimedia microblogging plus Twitter-style following.

Posterous Goes from instant microblogging into lifestreaming.

Soup A “super-easy” tumblelog for scrapbook keeping and lifestreaming.

Blogger Fast way to start blogging; training wheels for WordPress.

Bloglines For reading web feeds. Smart and clean.

WordPress Free, and most importantly spam-free, blogging.


Do we all need five browsers nowadays?

Chrome Now here for Mac, and anticipating future world domination via Chrome OS.

Firefox  Everyone’s favourite is under attack from all sides.

Maxthon Based on IE code. If it stays “hip in China” it could reach a large global audience.


Everyone needs some relaxation. This is a visual one.

Dilbert It wouldn’t be so funny if it wasn’t so true.

XKCD Stick-figure strip poking fun at geek topics and relationships.

Celebrity gossip

No one needs this stuff, but it’s starting to drive world news and web traffic.

TMZ Rose to fame when it broke news of Michael Jackson’s death.

Perez Hilton Among the bitchiest of goss sites and often involved in ‘interesting’ celeb baiting.

Gawker New York-based media alert and gossip blog network, with fingers in many pies.


With all of us now living more of our lives online, these sites just scratch the surface.

Netvibes Your to-do lists, news, weather and photos on one page.

Scribd Shares 35bn words online: they can’t all be wrong.

Slideshare Like YouTube for PowerPoint decks.

Zamzar Useful: converts files from one format to another.



Sites to see before heading for the latest blockbuster at your local multiplex.

IMDb The most authoritative site about all things film and TV, which is why Amazon bought it.

Rotten Tomatoes Collects online film reviews, aggregates a score out of 100 and rates the film “fresh” or “rotten”.

/Film Said to be the favourite film blog of directors Jason Reitman and Darren Aronofsky, /Film features news, reviews, interviews and a special UK update each Friday.

Cinematical Terrific film blog with a Hollywood focus.


A field where handheld, bedroom and Flash games are becoming mainstream

Eurogamer Reportage, with breadth, if not always depth.

The Independent Gaming Source  A great place to pick up on tomorrow’s breakthrough Xbox Live Arcade, WiiWare and PSN hits.

Pocket Gamer Still by far the best site on handheld gaming.

Gamasutra  Where professional games creators hang out, and sometimes get jobs

Geek squad

Here be programmers …

Stack Overflow Where programmers gather to try to solve their problems.

The Daily WTF Daily dispatches from the coding warzone.

Joel On Software Essays by a former Microsoftie, now head of Fog Creek Software.

Government/public services/politics

Recycle Now Winner after a slight false start of the government’sShow Us A Better Way competition. What can you recycle close by?

British and Irish Legal Information Institute A database of laws. Only survives hand-to-mouth on voluntary donations; where’s yours?

What Do They Know? Makes filing a Freedom Of Information request as easy as sending an email. Too easy, some in power think.

Upmystreet All the detail on your area you could ever want.

They Work For You A site set up by volunteers to keep tabs on our elected members of parliament – and our unelected peers.

Link economy


With millions of links on the web, we all need sites for sharing the best ones.

Digg Still the reigning champion of where the latest internet memes are though not always polite.

Delicious The thinking person’s link aggregation site. We use it.

Popurls Aggregating the aggregators: the web in a window.

Metafilter Living if isolated proof that a site can be successful without pictures or video, and can also host thoughtful conversations.

Slashdot Now looking venerable and old, but “News for nerds” site with a jokey name (/.) still attracts a big, and often knowledgable, audience.

Techmeme Technology news chosen by computer, though it’s now refined by human editors.

Location, location

Services like these blossom with a mobile phone that can access the internet.

Dopplr “Share your future travel plans with friends and colleagues”, then find out if others will be there too.

Qype Localised search for pubs, restaurants, etc; also a bit of a social network.

Loopt “Transforms your mobile phone into a social compass”.

Brightkite A “location-based social network”.


The flipside of location-based services: seeing where you are.

OpenStreetMap A rights-free map created by people like you. Remarkably detailed and precise.

Google Maps Street View Virtual tourism with practical applications, too.

Money/finance/consumer fightback

We all need someone on our side.

Money Saving Expert Does what it says on the tin.

Say No to 0870 Direct-dial numbers, not expensive national-rate ones.

Consumer Direct Government site for consumers.

Music British-made, now CBS-owned, music recommendation station.

Amazon Now has its own MP3 store in the UK as well as the US.

Hype Machine Picks up the latest news by tracking the music blogs.

Pitchfork The magazine of the music web, now with video, and lots of great lists.



The Onion Still the satirical newspaper of record. If it’s not in the Onion, it’s probably happened.

B3TA Beyond classification; its forum has spawned many memes … and more than its fair share of trolls.

Lolcats respite from stress with daft cCaptioned cats and other animals.

News Lite respite from stress with daft cGreat source of news that’s much too trivial to print.

Oddee Setting an internet standard for sets of curious and mildly amusing pictures, not cats.

PostSecret Notes of secrets sent by people who want them posted. So they are.

Passive-Aggressive Notes Would it be too much trouble for you to have a look?


Flickr The granddaddy of photo-sharing sites.

Picnik Photo editing in your browser.

Picasa Google’s photo organisation and editing tool.

DPreview The web’s best guide to cameras. Now Amazon owned.


CIA Factbook All the data you need on pretty much anywhere.

Wikipedia the gradually growing user-edited encyclopaedia is Still a first port of call on most topics.

Internet Archive/Wayback Machine The web in aspic. Useful for research into how the web used to look.

Metacritic Aggregates reviews of movies and DVDs, TV programmes, music and games

Wikileaks Anonymous source of a huge range ofleaked documents. If you dig, there’s something important there


Google dominates but Bing is challenging, and Yahoo and Microsoft are left in the dust.

Google So good it’s become almost synonymous with search.

Bing  Microsoft would like you to bing it, but its “decision engine” still has a long way to go.

Wolfram Alpha An “answer engine”that delivers when it has the data, but not that easy to use.

Social software

Two years ago it was nascent; now it’s embedded in our culture. Chances are high you’re a member of at least one, and perhaps all, of these sites.

Facebook Still changing and growing to become not just your home on the web, but your ID provider.

LinkedIn Contact sports for business users.

Ning One place to start your own social network – just as Madonna did – though it has yet to really take off.


Expedia Still the daddy when it comes to travel sites, and particularly good if you can bundle a flight with a hotel and other services.

TripAdvisor Essential reading for the user reviews of hotels, but it now covers much more.

Laterooms Specialises in hotel discounts.

Twitter, and associated


Twitter has proved itself over and over this year, from the Chinese earthquke to the Mumbai attacks to the Madoff fraud as a vector for news.

Twitter The ur-site, where you can create an identity (or several).

Twitter Creates your personal newspaper based on your friend’s tweets.

Twitterfeed Posts blog contents to Twitter.

TwitterCounter Graphs the growth in your followers.

Twitterfall Tracks trending topics; enables custom searches.

Listorious Twitter lists make it simple to follow large groups of Twitter users, and Listorious makes it easy to find the best lists.


YouTube Dominant provider of video content online.

Vimeo Better rights control than YouTube and a cleaner interface

BBC iPlayer The king of the online catchup services.

Hulu The networks fight back with their own video site, which may make the UK in 2010. We hope.

Videojug The motherlode of instructional videos, all in one place.

Virtual worlds

Second Life Continues to exist and is, apparently, still popular, but not the media darling it was.

Entropia Universe Set in a distant future on the untamed planet of Calypso.

Club Penguin Minigame-tastic virtual world for youngkids.

Moshi Monsters “Educational” virtual world for kids.

Visual arts

Saatchi Gallery Gallery, listings and artworks for sale.

Art Daily The first “art newspaper” on the net.

Culture 24 Everything about UK galleries and museums.


Information is Beautiful Creating effective infographics is one of today’s key skills, and on this site, it’s also an art. An archive of some of the finest examples of “information aesthetics”.

DabbleDB Create online databases and analyse them.

 Which essential sites have we missed? Tell us below

 This article was amended on Wednesday 9 December 2009. Picasa is no longer for Windows only; is no longer operational. These have been corrected.


refer to:


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好烂啊有点差凑合看看还不错很精彩 (No Ratings Yet)
Making Photos Smaller Without Quality Loss – by Yelp

Making Photos Smaller Without Quality Loss – by Yelp

Making Photos Smaller Without Quality Loss

Yelp has over 100 million user-generated photos ranging from pictures of dinners or haircuts, to one of our newest features, #yelfies. These images account for a majority of the bandwidth for users of the app and website, and represent a significant cost to store and transfer. In our quest to give our users the best experience, we worked hard to optimize our photos and were able to achieve a 30% average size reduction. This saves our users time and bandwidth and reduces our cost to serve those images. Oh, and we did it all without reducing the quality of these images!


Yelp has been storing user-uploaded photos for over 12 years. We save lossless formats (PNG, GIF) as PNGs and all other formats as JPEG. We use Python and Pillow for saving images, and start our story of photo uploads with a snippet like this:

With this as a starting point, we began to investigate potential optimizations on file size that we could apply without a loss in quality.


First, we had to decide whether to handle this ourselves or let a CDN provider magically change our photos. With the priority we place on high quality content, it made sense to evaluate options and make potential size vs quality tradeoffs ourselves. We moved ahead with research on the current state of photo file size reduction – what changes could be made and how much size / quality reduction was associated with each. With this research completed, we decided to work on three primary categories. The rest of this post explains what we did and how much benefit we realized from each optimization.

  1. Changes in Pillow
    • Optimize flag
    • Progressive JPEG
  2. Changes to application photo logic
    • Large PNG detection
    • Dynamic JPEG quality
  3. Changes to JPEG encoder
    • Mozjpeg (trellis quantization, custom quantization matrix)

Changes in Pillow

Optimize Flag

This is one of the easiest changes we made: enabling the setting in Pillow responsible for additional file size savings at the cost of CPU time (optimize=True). Due to the nature of the tradeoff being made, this does not impact image quality at all.

For JPEG, this flag instructs the encoder to find the optimal Huffman coding by making an additional pass over each image scan. Each first pass, instead of writing to file, calculates the occurrence statistics of each value, required information to compute the ideal coding. PNG internally uses zlib, so the optimize flag in that case effectively instructs the encoder to use gzip -9 instead of gzip -6.

This is an easy change to make but it turns out that it is not a silver bullet, reducing file size by just a few percent.

Progressive JPEG

When saving an image as a JPEG, there are a few different types you can choose from:

  • Baseline JPEG images load from top to bottom.
  • Progressive JPEG images load from more blurry to less blurry. The progressive option can easily be enabled in Pillow (progressive=True). As a result, there is a perceived performance increase (that is, it’s easier to notice when an image is partially absent than it is to tell it’s not fully sharp).

Additionally, the way progressive files are packed generally results in a small reduction to file size. As more fully explained by the Wikipedia article, JPEG format uses a zigzag pattern over the 8×8 blocks of pixels to do entropy coding. When the values of those blocks of pixels are unpacked and laid out in order, you generally have non-zero numbers first and then sequences of 0s, with that pattern repeating and interleaved for each 8×8 block in the image. With progressive encoding, the order of the unwound pixel blocks changes. The higher value numbers for each block come first in the file, (which gives the earliest scans of a progressive image its distinct blockiness), and the longer spans of small numbers, including more 0s, that add the finer details are towards the end. This reordering of the image data doesn’t change the image itself, but does increase the number of 0s that might be in a row (which can be more easily compressed).

Comparison with a delicious user-contributed image of a donut (click for larger):

(left) A mock of how a baseline JPEG renders.

(left) A mock of how a baseline JPEG renders.

(right) A mock of how a progressive JPEG renders.

(right) A mock of how a progressive JPEG renders.

Changes to Application Photo Logic

Large PNG Detection

Yelp targets two image formats for serving user-generated content – JPEG and PNG. JPEG is a great format for photos but generally struggles with high-contrast design content (like logos). By contrast, PNG is fully-lossless, so great for graphics but too large for photos where small distortions are not visible. In the cases where users upload PNGs that are actually photographs, we can save a lot of space if we identify these files and save them as JPEG instead. Some common sources of PNG photos on Yelp are screenshots taken by mobile devices and apps that modify photos to add effects or borders.

(left) A typical composited PNG upload with logo and border. (right) A typical PNG upload from a screenshot.

(left) A typical composited PNG upload with logo and border. (right) A typical PNG upload from a screenshot.

We wanted to reduce the number of these unnecessary PNGs, but it was important to avoid overreaching and changing format or degrading quality of logos, graphics, etc. How can we tell if something is a photo? From the pixels?

Using an experimental sample of 2,500 images, we found that a combination of file size and unique pixels worked well to detect photos. We generate a candidate thumbnail image at our largest resolution and see if the output PNG file is larger than 300KiB. If it is, we’ll also check the image contents to see if there are over 2^16 unique colors (Yelp converts RGBA image uploads to RGB, but if we didn’t, we would check that too).

In the experimental dataset, these hand-tuned thresholds to define “bigness” captured 88% of the possible file size savings (i.e. our expected file size savings if we were to convert all of the images) without any false-positives of graphics being converted.

Dynamic JPEG Quality

The first and most well-known way to reduce the size of JPEG files is a setting called quality. Many applications capable of saving to the JPEG format specify quality as a number.

Quality is somewhat of an abstraction. In fact, there are separate qualities for each of the color channels of a JPEG image. Quality levels 0 – 100 map to different quantization tables for the color channels, determining how much data is lost (usually high frequency). Quantization in the signal domain is the one step in the JPEG encoding process that loses information.

The simplest way to reduce file size is to reduce the quality of the image, introducing more noise. Not every image loses the same amount of information at a given quality level though.

We can dynamically choose a quality setting which is optimized for each image, finding an ideal balance between quality and size. There are two ways to do this:

  • Bottom-up: These are algorithms that generate tuned quantization tables by processing the image at the 8×8 pixel block level. They calculate both how much theoretical quality was lost and how that lost data either amplifies or cancels out to be more or less visible to the human eye.
  • Top-down: These are algorithms that compare an entire image against an original version of itself and detect how much information was lost. By iteratively generating candidate images with different quality settings, we can choose the one that meets a minimum evaluated level by whichever evaluation algorithm we choose.

We evaluated a bottom-up algorithm, which in our experience did not yield suitable results at the higher end of the quality range we wanted to use (though it seems like it may still have potential in the mid-range of image qualities, where an encoder can begin to be more adventurous with the bytes it discards). Many of the scholarly papers on this strategy were published in the early 90s when computing power was at a premium and took shortcuts that option B addresses, such as not evaluating interactions across blocks.

So we took the second approach: use a bisection algorithm to generate candidate images at different quality levels, and evaluate each candidate image’s drop in quality by calculating its structural similarity metric (SSIM) using pyssim, until that value is at a configurable but static threshold. This enables us to selectively lower the average file size (and average quality) only for images which were above a perceivable decrease to begin with.

In the below chart, we plot the SSIM values of 2500 images regenerated via 3 different quality approaches.

  1. The original images made by the current approach at quality = 85 are plotted as the blue line.
  2. An alternative approach to lowering file size, changing quality = 80, is plotted as the red line.
  3. And finally, the approach we ended up using, dynamic quality, SSIM 80-85, in orange, chooses a quality for the image in the range 80 to 85 (inclusive) based on meeting or exceeding an SSIM ratio: a pre-computed static value that made the transition occur somewhere in the middle of the images range. This lets us lower the average file size without lowering the quality of our worst-quality images.

SSIMs of 2500 images with 3 different quality strategies.

SSIMs of 2500 images with 3 different quality strategies.


There are quite a few image quality algorithms that try to mimic the human vision system. We’ve evaluated many of these and think that SSIM, while older, is most suitable for this iterative optimization based on a few characteristics:

  1. Sensitive to JPEG quantization error
  2. Fast, simple algorithm
  3. Can be computed on PIL native image objects without converting images to PNG and passing them to CLI applications (see #2)

Example Code for Dynamic Quality:

There are a few other blog posts about this technique, here is one by Colt Mcanlis. And as we go to press, Etsy has published one here! High five, faster internet!

Changes to JPEG Encoder


Mozjpeg is an open-source fork of libjpeg-turbo, which trades execution time for file size. This approach meshes well with the offline batch approach to regenerating images. With the investment of about 3-5x more time than libjpeg-turbo, a few more expensive algorithms make images smaller!

One of mozjpeg’s differentiators is the use of an alternative quantization table. As mentioned above, quality is an abstraction of the quantization tables used for each color channel. All signs point to the default JPEG quantization tables as being pretty easy to beat. In the words of the JPEG spec:

These tables are provided as examples only and are not necessarily suitable for any particular application.

So naturally, it shouldn’t surprise you to learn that these tables are the default used by most encoder implementations… 🤔🤔🤔

Mozjpeg has gone through the trouble of benchmarking alternative tables for us, and uses the best performing general-purpose alternative for images it creates.

Mozjpeg + Pillow

Most Linux distributions have libjpeg installed by default. So using mozjpeg under Pillow doesn’t work by default, but configuring it isn’t terribly difficult either. When you build mozjpeg, use the --with-jpeg8 flag and make sure it can be linked by Pillow will find it. If you’re using Docker, you might have a Dockerfile like:

That’s it! Build it and you’ll be able to use Pillow backed by mozjpeg within your normal images workflow.


How much did each of those improvements matter for us? We started this research by randomly sampling 2,500 of Yelp’s business photos to put through our processing pipeline and measure the impact on file size.

  1. Changes to Pillow settings were responsible for about 4.5% of the savings
  2. Large PNG detection was responsible for about 6.2% of the savings
  3. Dynamic Quality was responsible for about 4.5% of the savings
  4. Switching to the mozjpeg encoder was responsible for about 13.8% of the savings

This adds up to an average image file size reduction of around 30%, which we applied to our largest and most common image resolutions, making the website faster for users and saving terabytes a day in data transfer. As measured at the CDN:

Average filesize over time, as measured from the CDN (combined with non-image static content).

Average filesize over time, as measured from the CDN (combined with non-image static content).

What we didn’t do

This section is intended to introduce a few other common improvements that you might be able to make, that either weren’t relevant to Yelp due to defaults chosen by our tooling, or tradeoffs we chose not to make.


Subsampling is a major factor in determining both quality and file size for web images. Longer descriptions of subsampling can be found online, but suffice it to say for this blog post that we were already subsampling at 4:1:1 (which is Pillow’s default when nothing else is specified) so we weren’t able to realize any further savings here.

Lossy PNG encoding

After learning what we did about PNGs, choosing to preserve some of them as PNG but with a lossy encoder like pngmini could have made sense, but we chose to resave them as JPEG instead. This is an alternate option with reasonable results, 72-85% file size savings over unmodified PNGs according to the author.

Dynamic content types

Support for more modern content types like WebP or JPEG2k is certainly on our radar. Even once that hypothetical project ships, there will be a long-tail of users requesting these now-optimized JPEG/PNG images which will continue to make this effort well worth it.


We use SVG in many places on our website, like the static assets created by our designers that go into our styleguide. While this format and optimization tools like svgo are useful to reduce website page weight, it isn’t related to what we did here.

Vendor Magic

There are too many providers to list that offer image delivery / resizing / cropping / transcoding as a service. Including open-source thumbor. Maybe this is the easiest way to support responsive images, dynamic content types and remain on the cutting edge for us in the future. For now our solution remains self-contained.

Further Reading

Two books listed here absolutely stand on their own outside the context of the post, and are highly recommended as further reading on the subject.

来源: Making Photos Smaller Without Quality Loss

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如何构建一个中型的 web 应用(全栈技术)

计算机界的轮子已经如此之多,我的观点是技术不转化成应用是没有价值的,本文主要挑选了一些技术,复用一些优秀的轮子,用最小的成本构建自己的 web 应用。



boostrap twitter 出品的响应式框架,可以快速构建优美的前端界面

material-design-lite Google 出品的Material Design 风格的前端框架

前端库 /框架

jquery 方便快捷地操纵 dom


yog2 百度出品的前端构建工具,将fis3express结合在一起

webpack 当下最火的前端构建工具


nodejavascript 写后端应用


express node.js 官方推荐的 web 框架

koa express 原始团队出品,口碑很好,我并没有在实际项目中使用过


mysql 全球最流行的开源数据库,各大互联网公司都在大范围使用

mongo 时下最流行的 nosql 数据库,经过几年的发展已经很稳定了


knex mysql 的 node.js 版的 sql 构建库,需要搭配mysql 的 node.js 驱动 使用

mongoose mongo 的 node.js 版的数据库驱动


ansible 基于 ssh 的自动化部署工具,我还在摸索的阶段


ucloud 口碑不错的云服务商

阿里云 阿里巴巴旗下的云服务,号称国内最大

百度云 推荐一下自家公司的产品


七牛云 老牌云存储服务商,有免费额度



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InfoQ.com是由实践者驱动的社区媒体,我们的目标是: 推进和传播软件开发领域的知识和创新。 作为编辑兼实践者,我们参与成员驱动的编辑过程,向着这个共同目标努力前进,具体工作方式包括:翻译和撰写新闻,并以文章、采访、录制技术大会视频等多种形式分享知识。






来源: 让大家在InfoQ上听见你的声音

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后来,Steve Jobs – 史蒂夫·乔布斯对它的使用,使得它名声度越来越高。Jobs在为Macworld Conference and Expo,和其它苹果公司的活动中,在发表主题演讲时,都是使用自家的keynote。Jobs的特立独行、专注武断,以及他的对 Apple一系列产片的[美]的发掘和展现,使得苹果势头凶猛、营收累累。同时也直接、间接的带动了Keynote的传播。

Apple笔记本 – Mac Air、Mac Pro,等等,已经成为互联网界产品经理、美工、IOS 必备;随身带Mac,随手拿iPhone,随心Keynote展示PPT;已成各人zhuangbility利器。

所以,现在,每年国内国外有许许多多的互联网大会、Google大会、 Apple大会、特斯拉大会、Android大会、AWS大会,直接就以Keynote代替PPT了;就是说:Keynote就是PPT,PPT就是Keynote;你要是用PowerPoint,你都不好意思和人打招呼!



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做关键词外链 实在不行就做站群 多做些站 内容不要重复 但是内容要有相关性 做的外链都指向主站 但是子站之间不要相互链接





优化的好ip 8k UV 2.4w