Glyph Detection Range

Question

What is the average glyph detection range with the EZ-B v4 Camera?

Jeremie · Answer

Hello @pearsoe thanks for your interest, I'll see if I can do some real world tests with the v4 camera tomorrow.

Jeremie · Answer

@pearsoe It took me a while to get to this request but I finally did the tests today in the lab. Keep in mind that many factors play a role in this detection range like, lighting (brightness), contrast, and glyph size. That being said, we were able to reliably read a printed out glyph (on a 8x11" piece of paper) up to 15 feet away from the camera.

pearsoe · Answer

Thanks for the testing and update. Will there be an extension cable available for the EZ-B v4 camera or is it easy to build one yourself? What kind of connector does the camera use and how long could an extension cable be?

jstarne1 · Answer

I have successfully read even smaller 4 x 4" glyphs from 10 to 11 ft away. The only problem was lighting. I used 850nm leds pointed in the direction of the camera and then the cam could consistently read even QR codes at that distance. This was when I was experimenting with QR codes on the ceiling x IR readable.

hshahX · Answer

@jstarne1-XLRobots.com I am working with a group to make a robot that detects glyph markers on the ceiling of an area. We want each glyph to have a QR code printed on them in IR reflective ink that will reflect the light emitted from infrared LEDs that are pointed in the direction of an IR camera. Up until now we have been researching to just figure out if what we were attempting was possible but seeing your post is making us hopeful. Our main concern was with dimensions of the glyphs and how much range we could give the robot in detecting what the QR code said. 10 to 11 feet, as you specified would work very well for our purposes and knowing that the glyph is only 4x4" is even better since we expected it to be huge. We were wondering if you could direct us to materials to help us realize the physical part of this project, for example what type of IR reflective ink are you using for the glyphs? Thanks in advance!

jstarne1 · Answer

Ceiling QR code landmark robot navigation test 2: https://youtu.be/c7CzLF8z7uY I made 4 videos on QR code tests at distance. Qr code reading relies on the contrast different between the light areas and bold areas. They can be different colors or possibly reflective medium to mark the light areas agianst a non reflective back ground. I would love to use IR reactive paint as that would allow invisible QR codes anywhere in the home that your robot can illuminate. By any chance do you know the girl who commented on one of the videos close to the same time you posted here? First off you will want to consider a lens set to magnify or zoom in to get a really good view of small codes on the ceiling. Maybe a 2x or 4x. They are very cheap because the make stick on lenses for iphone cameras. It is something i noticed would allow for very small codes even at a good distance. In my experiments i used bright white cardstock paper sheets and normal printer ink. The v3 cam has a adjustable lense that allowed a manual focus but i believe the v4 version may have a fixed focus or limited digital software focus. Im interested in your project , can you tell me more about it? What are the long term goals of the ceiling codes?

hshahX · Answer

@jstarne1-XLRobots.com Yes the girl who commented is my partner on the project. We actually found out we were talking to the same person a little while ago, small world! We have spoken to our advisor and he has allowed us to use other inks/paints than simply IR reflective. We are considering the materials you posted to youtube as well. We particularly like the idea of using UV ink since that would still be unnoticeable to the human eye but would also be easier to find on the market. You mention using IR reactive paint, do you have an idea of how we would apply it to print the codes? Is there a service available or a specific printer we must purchase to print IR reactive ink? I'm sorry I don't understand what you are saying about the iPhone cameras, what do you mean by "make stick"? Our project will use the ceiling codes for indoor localization, we're trying to use one robot to build a map and then have another robot use the map data to navigate an area.

jstarne1 · Answer

https://www.amazon.com/gp/aw/d/B00H788ZN2?cache=2944060a8541061877d89e06933b6282&pi=AC_SX110_SY165_QL70&qid=1411509366&sr=8-4#ref=mp_s_a_1_4 here is an example. Cheap lens sets If you want the camera to be able to see smaller glyphs or further away these lenses are ideal to place over your original camera lens for a zoom effect. The fish eye wont be helpful for the QR code or gyph detection but most these lenses for the phones are sold in sets.

jstarne1 · Answer

Here is an 8x version for lots of zoom and focus. https://www.amazon.com/gp/aw/d/B0077J2HDK?cache=18cb6b74e56213cfbbe63a7b454b6330&pi=AC_SX110_SY165_QL70&qid=1411509859&sr=8-8#ref=mp_s_a_1_8

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