The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Photography & Images

Taking & making images.

  • Rail Trail Riding, With Road Rash

    The Dutchess Rail Trail sits atop a pipeline carrying water from the treatment plant in the City of Poughkeepsie to the GlobalFoundries (neé IBM East Fishkill) complex. For good engineering reasons, the mid-line pumping station (equipment yard visible to our left) in Page Industrial Park sits directly athwart the pipe, which forced an abrupt S-curve on a relatively steep slope into the rail trail layout.

    T=0.000 s — The lead cyclist just cut in front of her companion and isn’t leaning into the turn, at which point Mary and I both realize this isn’t going to end well:

    Road Rash 2015-08-15 - 131
    Road Rash 2015-08-15 – 131

    T=0.750 s — Newton grabs control of her bike and he’s not gonna let go:

    Road Rash 2015-08-15 - 176
    Road Rash 2015-08-15 – 176

    T=1.633 s — The rear wheel locks as she passes Mary, she’s far off-center and falling to her left, the bike has gone inertial, and it’s obvious we’re about to arrive at the same place at the same time:

    Road Rash 2015-08-15 - 229
    Road Rash 2015-08-15 – 229

    T=2.100 s — Collision Alarm! I’m veering off the pavement, which is the only reason we didn’t have an offset frontal collision:

    Road Rash 2015-08-15 - 257
    Road Rash 2015-08-15 – 257

    T=2.333 s — Impact! I’m stopped and balanced on the bike, with my left foot out of the pedal cleat and heading for the ground. She’s sliding past me, pivoting around her bike’s left pedal skidding on the asphalt:

    Road Rash 2015-08-15 - 271
    Road Rash 2015-08-15 – 271

    She ended up sprawled atop her bike, facing up the slope, with the front wheel just beside the rear wheel of my bike; her foot or some part of her bike whacked my left-side underseat bag in passing, but there was no bike-on-bike collision. No injuries for her, other than perhaps a bit of road rash, but only by sheer raw good fortune.

    Reviewing the video shows she lost control at the transition from the trail to the downward S-curve, a few seconds before the first picture here and about five seconds before she stopped sliding past my bike, but the problem wasn’t obvious until the scene in the first picture. Mary never had a chance to react and, with less than two seconds until the not-quite-collision, my gross-motor reaction time just barely got me out of the way.

    Brake early and always wear a helmet.

  • Testing USB Memory Devices

    Tantris recommended the f3 set of programs to verify USB memory devices, which certainly seemed as though it would be faster and much less labor-intensive than my low-tech manual method.

    Compiling it from source required installing two dependencies, which I discovered by the simple expedient of iteratively smashing into “fatal error: parted/parted.h: No such file or directory” messages:

    • libudev-dev
    • libparted0-dev

    With those in place, unleashing f3probe on the most recent replacement Sony 64 GB MicroSD card went swimmingly:

    sudo ./f3probe --time-ops /dev/sdb
    F3 probe 5.0
    Copyright (C) 2010 Digirati Internet LTDA.
    This is free software; see the source for copying conditions.
    Please unplug and plug back the USB drive. Waiting... Thanks
    Please unplug and plug back the USB drive. Waiting... Thanks
    Please unplug and plug back the USB drive. Waiting... Thanks
    Please unplug and plug back the USB drive. Waiting... Thanks
    Please unplug and plug back the USB drive. Waiting... Thanks
    Please unplug and plug back the USB drive. Waiting... Thanks
    CAUTION		CAUTION		CAUTION
    No more resets are needed, so do not unplug the drive
    Probe finished, recovering blocks... Done
    
    Good news: The device `/dev/sdb' is the real thing
    
    Device geometry:
    	        *Real* size: 60.37 GB (126613504 blocks)
    	     Announced size: 60.37 GB (126613504 blocks)
    	             Module: 64.00 GB (2^36 Bytes)
    	Physical block size: 512.00 Byte (2^9 Bytes)
    
    Probe time: 61.19 seconds
    Probe read op: count=775, total time=4.00s, avg op time=5.16ms
    Probe write op: count=753, total time=3.77s, avg op time=5.00ms
    Probe reset op: count=6, total time=53.42s, avg op time=8903.21ms
    

    As predicted, most of the time passed while I fiddled with the SD Card adapter in the slot on the side of the U2711 monitor: push to release, push to insert, repeat as prompted.

    Despite the f3fix program’s ability to “repair” counterfeit USB memory by resetting the partition to the actual capacity, I think that’s a Bad Idea. Based on my admittedly limited experience, counterfeit junk generally doesn’t come from the middle of the quality-control bell curve, so expecting that crap to actually work over the long term seems, shall we say, overconfident.

    The f3 doc also told me about lsblk, which may come in handy every now & again:

    lsblk
    NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
    sda      8:0    0 111.8G  0 disk 
    ├─sda1   8:1    0  56.8G  0 part /
    └─sda2   8:2    0   9.3G  0 part [SWAP]
    sdb      8:16   1  60.4G  0 disk 
    └─sdb1   8:17   1  60.4G  0 part /media/ed/9C33-6BBD
    sr0     11:0    1  1024M  0 rom 
    

    Now I have a reminder of how to do this for The Next Time…

  • Sharing the Road on Raymond Avenue: Part 3

    This truck driver gave us as much room as he possibly could, given the cramped conditions on Raymond Avenue:

    Raymond Ave - 2015-07-17 - Truck Clearance 1
    Raymond Ave – 2015-07-17 – Truck Clearance 1

    Notice the street lamp in view directly above the cab? Keep that in mind.

    In order to give us that much clearance, he had to put the left wheels up on the median:

    Raymond Ave - 2015-07-17 - Truck Clearance 2
    Raymond Ave – 2015-07-17 – Truck Clearance 2

    That’s exactly what the NYSDOT engineer who designed Raymond Avenue explained to me drivers should do. Driving on the median is the intent of the Raymond Avenue layout.

    FWIW, the “brick paver” median surface is actually stamped asphalt (or some thermoplastic material) painted brick red. It has marginal durability; the same material in the rotary islands began disintegrating after a few months, has accumulated many non-textured patches, and was obviously not intended to support routine travel.

    After that truck passed, the FedEx driver also gave us plenty of clearance, also with left wheels on the median:

    Raymond Ave - 2015-07-17 - Truck Clearance 3
    Raymond Ave – 2015-07-17 – Truck Clearance 3

    Notice the minimal clearance between that lamp post and the protruding driver-side mirror? You’re supposed to drive on the median to avoid cyclists, while simultaneously not colliding with a zero-clearance black lamp post.

    Those lamp posts replaced the original bollards bracketing the crosswalk (just ahead of Mary in the first picture). Those bollards stood directly in the pseudo-brick area on both sides of the travel lane, with zero clearance from the inclined curb and roughly in line with those truck headlights: anyone driving up on the median at the crossing to avoid a cyclist would mow down a nonreflective black bollard.

    And, indeed, mowed down they were.

    A few years ago, NYSDOT removed the bollards from the “pedestrian refuges” (that’s their term for the crosswalk median area) and repositioned the remainder in the center of the median, presumably to protect them from drivers.

    Share the road, that we do…

  • Verifying Yet Another Sony 64 GB MicroSD Card

    The replacement for the second failed Sony SR-64UY MicroSD card arrived:

    Sony SR-64UX 64 GB MicroSDXC card
    Sony SR-64UX 64 GB MicroSDXC card

    The previous cards were made in Korea, but this one came from Taiwan with a different serial number format:

    Sony SR-64UX 64 GB MicroSDXC card - back
    Sony SR-64UX 64 GB MicroSDXC card – back

    The tiny letters on the front identify it as an SR-64UX, but I haven’t been able to find any definitive Sony source describing the various cards; their catalog page listing cards for digital still cameras may be as good as it gets. This one seems to have a higher read speed, for whatever little good that may do.

    It stored and regurgitated the usual deluge of video files with no problem, which is only to be expected. This time around, I checked the MD5 sums, rather than unleashing diff on the huge files:

    cd /media/ed/9C33-6BBD/
    for f in * ; do find /mnt/video/ -name $f | xargs md5sum $f ; done
    11e31c9ba3befbef6dd3630bb68064d6 MAH00539.MP4
    11e31c9ba3befbef6dd3630bb68064d6 /mnt/video/2015-07-05/MAH00539.MP4
    ... snippage ...
    

    It now sits in the fancy plastic display case that the HDR-AS30V camera came in until the previous replacement card fails.

  • Traffic Signal Timing: Burnett Blvd. at Rt 55

    Adapted from an email to NYSDOT (hvtmc@dot.state.ny.us):

    The minimum green and yellow times on the signals from Burnett Blvd to Rt 55 are too short for bicycle traffic making a left turn across six traffic lanes.

    The pictures show key points from our ride on 2015-07-10, returning from the Balloon Festival in Poughkeepsie. We took the DCRT around Poughkeepsie, went through Arlington to Rt 376 at Collegeview, then took Rt 376 Red Oaks Mill.

    The image sequence numbers identify frames extracted from video files. The front camera (a Sony HDR-AS30V) runs at 60 fps and the rear camera (a Cycliq Fly6) at 30 fps, so you can directly calculate the time between frames. The Fly6 timestamp is one hour ahead, for reasons I don’t quite understand.

    The red signals are turning off and the greens haven’t lit up yet:

    Burnett at Rt 55 Signal - Front 0196
    Burnett at Rt 55 Signal – Front 0196

    One second later, the car and our bikes are starting to roll:

    Burnett at Rt 55 Signal - Front 0260
    Burnett at Rt 55 Signal – Front 0260

    Given the number of drivers blowing through red signals at full speed, devoting one second to watching for oncoming traffic seems prudent.

    The yellow signals begin turning on seven seconds after the green:

    Burnett at Rt 55 Signal - Front 0633
    Burnett at Rt 55 Signal – Front 0633

    The car has reached the pedestrian ladder across Rt 55, but we’re still crossing the westbound lanes of traffic. Note that I’m lined up with the lane closest to our starting point on Burnett: this is a big intersection. We may not be the fastest riders on the road, but we’re not the slowest, either.

    We’ve reached the far side of the intersection just under 16 seconds from the green:

    Burnett at Rt 55 Signal - Front 1142
    Burnett at Rt 55 Signal – Front 1142

    However, the opposing signals turned green while we’re still crossing the eastbound lanes of Rt 55, 15 seconds after the Burnett Blvd signals went green:

    Burnett at Rt 55 Signal - Rear 0408
    Burnett at Rt 55 Signal – Rear 0408

    About 2.7 seconds later, cars have been accelerating across the intersection toward us as we reach the pedestrian ladder:

    Burnett at Rt 55 Signal - Rear 0490
    Burnett at Rt 55 Signal – Rear 0490

    They started rolling immediately after their signal went green; waiting a second isn’t a universal practice.

    Setting the minimum Burnett green to 12 seconds, the minimum yellow to 10 seconds, and the minimum delay from Burnett green to Rt 55 green to 30 seconds would help cyclists (just barely) reach the far side of the intersection before opposing traffic starts rolling.

    As a bonus, adjusting the sensor amplifiers on Burnett to respond to bicycles and marking the coil locations on the pavement in both lanes would help us through the intersection during low-traffic-volume times, as our bikes seem unable to trip the signals.

  • On the Cutting Edge of Metal Recycling

    A semitrailer load of scrap metal pulled into an I-90 rest stop just after we arrived:

    Metal scrap trailer - Cutting edge
    Metal scrap trailer – Cutting edge

    Apparently, they dump the scrap into the trailer from a great height and, sometimes, a bar can gash the aluminum side wall. That slice obviously predates the current load, but you can see how it happened: dump a load atop a bar leaning against the side and you get a giant metal shear.

    The trailer also had several puncture wounds:

    Metal scrap trailer - Puncture wounds
    Metal scrap trailer – Puncture wounds

    I didn’t notice the circular feature at the bottom center until I looked at the picture, but it certainly reminded me of a bullet hole in glass plate. Close inspection of the original image suggests it’s a welded stress relief border around a drilled hole, perhaps with a boss on the inside of the trailer:

    Metal scrap trailer - Welded hole
    Metal scrap trailer – Welded hole

    Ya never know what you’ll find out on the road…

  • ImageMagick: Compressing to a Fixed File Size

    Verily, ImageMagick can do nearly anything you want to an image, as long as you know how to ask for it:

    for f in *png ; do convert $f -density 300 -define jpeg:extent=200KB ${f%%.*}.jpg ; done
    

    That converts a directory full of VLC’s video snapshot images from PNG format, which require nigh onto 4 MB each, into correspondingly named JPG files under 200 kB. The image quality may not be the greatest, but it’s good enough to document road hazards in emails.

    Rt 376 2015-07-06 - Walker to Maloney - 3
    Rt 376 2015-07-06 – Walker to Maloney – 3

    The density option overrides VLC’s default 72 dpi, which doesn’t matter until a program attempts to show the image at “actual size”.

    I didn’t realize that the define option existed, but it seems to be how you jam specific controls into the various image coders & decoders. Some of the “artifacts”, well, I can’t even pronounce…

    VLC’s snapshot file names look like vlcsnap-2015-07-06-12h10m27s10.png, so bulk renaming and resequencing will be in order.