Categories describing the post, video, pictures, audio…

WebP and SVG

Tuesday, September 1, 2020 

Using WebP coded images inside SVG containers works.  I haven’t found any automatic way to do it, but it is easy enough manually and results in very efficiently coded images that work well on the internets.  The manual process is to Base64 encode the WebP image and then open the .svg file in a text editor and replace the

xlink:href="data:image/png;base64, ..."

with

xlink:href="data:image/webp;base64,..."

(“…” means the appropriate data, obviously).


Back in about 2010 Google released the spec for WebP, an image compression format that provides a roughly 2-4x coding efficiency over the venerable JPEG (vintage 1974), derived from the VP8 CODEC they bought from ON2. VP8 is a contemporary of and technical equivalent to H.264 and was developed during a rush of innovation to replace the aging MPEG-II standard that included Theora and Dirac. Both VP8 and H.264 CODECs are encumbered by patents, but Google granted an irrevocable license to all patents, making it “open,” while H.264s patents compel licensing from MPEG-LA.  One would think this would tend to make VP8 (and the WEBM container) a global standard, but Apple refused to give Google the win and there’s still no native support in Apple products.

A small aside on video and still coding techniques.

All modern “lossy” (throwing some data away like .mp3, as opposed to “lossless” meaning the original can be reconstructed exactly, as in .flac) CODECs are founded on either Discrete Cosine Transform (DCT) or Wavelet (DWT) encoding of “blocks” of image data.  There are far more detailed write ups online that explain the process in detail, but the basic concept is to divide an image into small tiles of data then apply a mathematical function that converts that data into a form which sorts the information from least human-perceptible to most human-perceptible and sets some threshold for throwing away the least important data while leaving the bits that are most important to human perception.

Wavelets are promising, but never really took off, as in JPEG2000 and Dirac (which was developed by the BBC).  It is a fairly safe bet that any video or still image you see is DCT coded thanks to Nasir Ahmed, T. Natarajan and K. R. Rao.  The differences between 1993’s MPEG-1 and 2013’s H.265 are largely around how the data that is perceptually important is encoded in each still (intra-frame coding) and some very important innovations in inter-frame coding that aren’t relevant to still images.

It is the application of these clever intra-frame perceptual data compression techniques that is most relevant to the coding efficiency difference between JPEG and WebP.

Back to the good stuff…

Way back in 2010 Google experimented with the VP8 intra-coding techniques to develop WebP, a still image CODEC that had to have two core features:

  • better coding efficiency than JPEG,
  • ability to handle transparency like .png or .tiff.

This could be the one standard image coding technique to rule them all – from icons to gigapixel images, all the necessary features and many times better coding efficiency than the rest.  Who wouldn’t love that?

Apple.

Of course it was Apple.  Can’t let Google have the win.  But, finally, with Safari 14 (June 22, 2020 – a decade late!) iOS users can finally see WebP images and websites don’t need crazy auto-detect 1974 tech substitution tricks.  Good job Apple!

It may not be a coincidence that Apple has just released their own still image format based on the intra-frame coding magic of H.265, .heif and maybe they thought it might be a good idea to suddenly pretend to be an open player rather than a walled-garden-screw-you lest iOS insta-users wall themselves off from the 90% of the world that isn’t willing to pay double to pose with a fashionable icon in their hands.  Not surprisingly, .heic, based on H.265 developments is meaningfully more efficient than WebP based on VP8/H.264 era techniques, but as it took WebP 10 years to become a usable web standard, I wouldn’t count on .heic  having universal support soon.  I expect Google is hard at work on a VP9-based version of WebP right now.  Technology is fast, marketing is slow.  Oh well.  In the mean time….

SVG support in browsers is a much older thing – Apple embraced it early (SVG was not developed by Google so….) and basically everything but IE has full support (IE…  the tool you use to download a real browser).  So if we have SVG and WebP, why not both together?

Oddly I can’t find support for this in any of the tools I use, but as noted at the open, it is pretty easy.  The workflow I use is to:

  • generate a graphic in GIMP or Photoshop or whatever and save as .png or .jpg as appropriate to the image content with little compression (high image quality)
  • Combine that with graphics in Inkscape.
  • If the graphics include type, convert the type to SVG paths to avoid font availability problems or having to download a font file before rendering the text or having it render randomly.
  • Save the file (as .svg, the native format of Inkscape)
  • Convert the image file to WebP with a reasonable tool like Nomacs or Ifranview.
  • Base64 encode the image file, either with base64 # base64 infile.webp > outfile.webp.b64 or with this convenient site
  • If you use the command line option the prefix to the data is “data:image/webp;base64,
  • Replace the … on the appropriate xlink:href="...." with the new data using a text editor like Atom.
  • Drop the file on a browser page to see if it works.

WordPress blocks .svg uploads without a plugin, so you need one

The picture is 101.9kB and tolerates zoom quite well. (give it a try, click and zoom on the image).

 

Posted at 08:54:16 GMT-0700

Category: HowToLinuxphotoself-publishingtechnology

Dealing with Apple Branded HEIF .HEIC files on Linux

Saturday, August 22, 2020 

Some of the coding tricks in H.265 have been incorporated into MPEG-H coding, an ISO standard introduced in 2017, which yields a roughly 2:1 coding efficiency gain over the venerable JPEG, which was introduced in 1992.  Remember that?  I do; I’m old.  I remember having a hardware NUBUS JPEG decoder card.   One of the reasons JPEG has lasted so long is that images have become a small storage burden (compared to 4k video, say) and that changing format standards is extremely annoying to everyone.

Apple has elected to make every rational person’s life difficult and put a little barbed wire around their high-fashion walled garden and do something a little special with their brand of a HEVC (h.265) profile for images.  Now normally seeing iOS user’s insta images of how fashionable they are isn’t really worth the effort, but now and then a useful correspondent joins the cult and forks over a ton of money to show off a logo and starts sending you stuff in their special proprietary format.  Annoying, but fixable.

Assuming you’re using an OS that is neither primarily spyware nor fashion forward, such as Linux Mint, you can install HEIF decode (including Apple Brand HEIC) with a few simple commands:

$ sudo add-apt-repository ppa:jakar/qt-heif
$ sudo apt update
$ sudo apt install qt-heif-image-plugin

Once installed, various image viewers should be able to decode the images.  I rather like nomacs as a fairly tolerable replacement for Irfan Skiljan‘s still awesome irfanview.

Posted at 03:56:36 GMT-0700

Category: HowToLinuxphotoPositivereviewstechnology

1976 GMC Suburban

Friday, May 17, 2019 

When I was a young child, my dad bought a brand new 1976 GMC Suburban. Yellow. No extras at all – no head liner, plastic seats, manual everything, 305 V8.

It became my car in high school, survived that. Came out to California with me; ended up in the service of SRL, survived that too.

Eventually, it escaped.

Posted at 13:18:33 GMT-0700

Category: photoSRL

The Daily, from the NYT, weirdly slow

Saturday, December 30, 2017 

From my distant location overseas, listening to the news via podcasts is a great way to keep up: something I’m quite grateful to have access to on demand and via the internets.   Until the end of Net Neutrality means that only “Verizon Insights” and “Life at AT&T” are still accessible, I enjoy a range of news sources on a daily basis using a podcatcher called Beyond Pod.  One of the essential features it has is the ability to speed up the tempo of podcasts, some of which are a bit slow as recorded.  But one…. one is like dripping molasses on a winter day: The Daily from the NYT by Michael Barbaro.  I’m pretty sure silences are inserted in editing to draw out the drama to infuriating lengths and the tempo of the audio is selectively slowed to about half normal speed.  Nobody can actually talk that slowly.  I mean listen and try – like actually try to draw out a word that might take 1 second to pronounce to two full seconds.   It is a pretty good news summary and has some useful information, but there’s no way I’d suffer through it without setting the tempo to 2x.

Every time I accidentally stream the podcast, rather than downloading and playing, the tempo control is disabled and while I scramble to skip to the next podcast before my I start questioning reality I often wonder for a moment just how bad the pauses are.  Here’s my analysis:

I consider the BBC Global News to be a very professional, truly “broadcast quality” podcast.  The announcers are clear, comprehensible, and speak at a pace that is appropriate for a news broadcast.  I still speed it up because daily life is like that now, but if I listen at normal pace, it isn’t even slightly annoying.

The Economist Radio is fairly typical of a print publication’s efforts at presenting print journalists as audio stars.  it doesn’t always work out perfectly and the pacing varies a lot by who is speaking and the rather eclectic line-up.  In general it is annoyingly slow, but not interminably so.  It comes across as a bit amateur by broadcast standards, but well done and very informative.

But then there’s The Daily from the NYT.  This podcast was the reason I took the time to figure out how to speed up playback.  There was no other choice: either unsubscribe or speed it up to something not aneurysm inducing.  Looking at the waveforms, I suspect they might actually be inserting silences of around 500msec between words, perhaps for dramatic effect (there’s way too much dramatic effect in a lot of the stories, which speeding up only hastens rather than fully alleviating—never have you heard so many interviewees break into uncomfortable tears as they’re overwhelmed by whatever the day’s tragedy is, an artifice only slightly less annoying than broadcasting the sound of someone eatingOMG, that’s real.  Rule 34.)

Read more…

Posted at 07:42:26 GMT-0700

Category: Audiotechnology

Kitty Poop

Tuesday, June 27, 2017 

Many years ago (21 years, 9 months as of this post), I used some as-of-then only slightly out of date equipment to record a one week time lapse of the cats’ litter box.

I found the video on a CD-ROM (remember those?) and thought I’d see if it was still usable. It wasn’t – Quicktime had abandoned support for most of the 1990’s era codecs, and as it was pre-internet, there just wasn’t any support any more. I had to fire up my old Mac 9500, which booted just fine after years of sitting, even if most of the rubber feet on the peripherals had long since turned to goo. The OS9 version of QT let me resave as uncompressed, which of course was way too big for the massive dual 9GB drives in that machine. Youtube would eat the uncompressed format and this critical archival record is preserved for a little longer.

Posted at 15:16:46 GMT-0700

Category: catsfilmsfunnyoddself-publishingvanity sitesvideo

Green Lacewings

Sunday, January 10, 2016 

I noticed that my avocado tree was developing brown spots on the leaves, which were almost certainly the result of Persea mites.

Leaf Symptoms

 

So I looked up some possible cures, and it seemed like introducing a predator would be the best option and the least hassle.  I’d had good luck with introduced ladybugs a few years back, which formed a stable population that survived for many years after introduction.  For this pest, green lacewings are recommended.  I found a nearby insectary that could provide larvae on cards and they shipped them overnight.

Green Lacewing egg cards

 

 

The little guys look cute just waiting to hatch…

Green Lacewing Eggs

 

I hung he cards on the leaves of the tree after incubating them overnight in a warm room, and they should hatch sometime in the next day or two, as long as the ants don’t find them first…

Card in tree

 


Update 8 Sept 2016:

The green lacewings seem to have eaten all the mites.  It has been 9 months and there aren’t any signs of damage to this spring’s leaves.  Yay!

No mite bites

The new leaves that grew seem to be developing without any bites at all.  The old leaves that were too damaged have fallen off, but the surviving older leaves still show the scars of the mites.  Green lacewings seem to have done the trick.

Posted at 14:40:47 GMT-0700

Category: photoPositivereviews

United’s Magic Trays

Thursday, September 3, 2015 

@United has new coach trays that are coated with a material that has an amazing coefficient of friction.  They are not sticky at all—there’s no adhesion effect—it is all friction.  Even low surface energy plastics don’t slide on it at all.

The approximately 75-80° angle in the picture is the point at which the cup topples over itself.  It isn’t adhered to the surface and it doesn’t appear to slide at all before toppling.

Super Friction Tray

This would be the perfect coating for a smart phone pad in a car.

Posted at 11:00:39 GMT-0700

Category: Fabricationphotoplanestechnologytravel

Summer Blooms

Friday, July 24, 2015 

Roses Bird of Paradise Closeup Bird of Paradise Blooms Cactus Blooms

Posted at 13:41:13 GMT-0700

Category: photoweather

Tortuga Stalking the Yard

Thursday, July 23, 2015 

Tortuga Profile

Tortuga quarter

Tortuga facing

Posted at 01:24:04 GMT-0700

Category: catsphoto

The Avocado Tree is Fruiting

Tuesday, July 21, 2015 

A couple of years back a random sprout appeared in the yard. It looked like a volunteer avocado and grew bizarrely fast. After a few years, it is about 15′ tall and this year it fruited for the first time. It really is an avocado tree.
 

Avacado Tree Fruiting

 

Posted at 23:15:30 GMT-0700

Category: photo