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Why are we even using black and white tags? https://austingwalters.com/chromatags/ https://austingwalters.com/chromatags/

charcircuit 3y ago
Because printing binary black and white is cheaper to print and cheaper to read.
- 1letterunixname 3y ago
  That was the case in 2005, but now nearly every camera in public and industrial use supports color except save some in particular logistics uses that would need upgrading. The only reason it remains is legacy and convention. Yes, it requires different printers, but that's not an insurmountable supply chain change, especially if it's reduced to a few distinct colors that don't need to be mixed. This is a missed opportunity to encode more data into a given area and/or to make it more readable.
  - p3n1s 3y ago
    > nearly every camera in public and industrial use supports color This is essentially false. Plenty of industrial cameras are black and white because of their speed and light collecting advantages. This matters for high speed identification. Going to color would not be an upgrade. "missed opportunity" Limited information density just isn't nearly as big an issue as you seem to believe. Colors work great until they don't, for non emissive sources they depend on ambient lighting. A black and white code can be read with under virtually any color lighting (it doesn't even have to be in the visible spectrum). And if you've seen anyone futzing getting a read of an eticket off an emissive device such as a screen, that is just much worse once color is brought in. Most auto ID applications have limited keys and identifiers encoded in the symbol. Just as color cameras are ubiquitous, the same goes for network connectivity, you don't need to store massive amounts of data in the symbol. If color symbols were really that much of a win they would have been adopted in industry. Attempts by groups that don't understand the subject have been made over the years, this is not new: https://en.wikipedia.org/wiki/High_Capacity_Color_Barcode https://en.wikipedia.org/wiki/High_Capacity_Color_Barcode "Yes, it requires different printers" This is quite an understatement. There's no cheap upgrade path from monochrome thermal printing technology (or laser engraving), that's why they have never been replaced all these years. Color imagers were readily available long before 2005. Color printing has not changed much at all in the past 20 years. If color symbols made sense they would have been adopted a long time ago. They are almost always the wrong approach, too many problems for too little payoff, that's why they are uncommon.
  - Dylan16807 3y ago
    Cameras sensors can pick up denser patterns in black and white, especially under imperfect lighting, and the extra data density is not all that much.
  - jandrese 3y ago
    Anybody who has tried to color correct for lighting conditions is shaking their head at this idea. Dealing with color is always a headache.
  - kccqzy 3y ago
    Humans can't even reliably tell whether a dress is black and blue, or it is white and gold. Color is complicated.
scrollaway 3y ago
Chromatags probably have their uses, but when put in practice like qr codes are, they don't have most of the "features". Monochrome means you can use cheap/shitty printers, you can theme them to go well with your brand, etc.
femto 3y ago
Same reason we use binary computers? The greater noise margin on each bit typically offsets the requirement to have more/smaller/shorter bits compared to a multilevel signal.
nwallin 3y ago
Printing. Printing is done in the CMYK color space. Cyan, Magenta, Yellow, blacK. When you print in color, it is basically four different printers printing onto the same piece of paper. Ideally everything is all lined up correctly, but if you want to do it on an industrial scale, good alignment costs time and money. Big printed color color posters tend to have shitty alignment. A color tag needs to have good alignment; if the cyan, magenta, yellow print runs are misaligned, chances are a color tag won't be able to read it. But the black run is always aligned to the black run. So it will always work. Lighting. The Sun, incandescent, and halogen lights have pretty good color reproduction. But LED lights and fluorescent lights do not. LED lights and fluorescent lights are designed to look acceptable to human eyes. And they can be reasonably good at it. But cameras are not human eyes; color gets all fucky when you look at it through a camera. Cameras. The tag you linked to uses the LAB color space; one channel is brightness, one channel is blue vs yellow, one channel is red vs green. Cameras almost always have BGGR arrays; on a 4 megapixel camera, you will have 1 million blue pixels, 2 million green pixels, and 1 million red pixels. So if you use a normal camera to read a tag in the LAB space, you have 4 million pixels reading the brightness channel, 3 million pixels reading the red-green channel, and 1 million pixels reading the blue-yellow channel.

charcircuit 3y ago

Because printing binary black and white is cheaper to print and cheaper to read.

1letterunixname 3y ago
That was the case in 2005, but now nearly every camera in public and industrial use supports color except save some in particular logistics uses that would need upgrading. The only reason it remains is legacy and convention. Yes, it requires different printers, but that's not an insurmountable supply chain change, especially if it's reduced to a few distinct colors that don't need to be mixed. This is a missed opportunity to encode more data into a given area and/or to make it more readable.
- p3n1s 3y ago
  > nearly every camera in public and industrial use supports color This is essentially false. Plenty of industrial cameras are black and white because of their speed and light collecting advantages. This matters for high speed identification. Going to color would not be an upgrade. "missed opportunity" Limited information density just isn't nearly as big an issue as you seem to believe. Colors work great until they don't, for non emissive sources they depend on ambient lighting. A black and white code can be read with under virtually any color lighting (it doesn't even have to be in the visible spectrum). And if you've seen anyone futzing getting a read of an eticket off an emissive device such as a screen, that is just much worse once color is brought in. Most auto ID applications have limited keys and identifiers encoded in the symbol. Just as color cameras are ubiquitous, the same goes for network connectivity, you don't need to store massive amounts of data in the symbol. If color symbols were really that much of a win they would have been adopted in industry. Attempts by groups that don't understand the subject have been made over the years, this is not new: https://en.wikipedia.org/wiki/High_Capacity_Color_Barcode https://en.wikipedia.org/wiki/High_Capacity_Color_Barcode "Yes, it requires different printers" This is quite an understatement. There's no cheap upgrade path from monochrome thermal printing technology (or laser engraving), that's why they have never been replaced all these years. Color imagers were readily available long before 2005. Color printing has not changed much at all in the past 20 years. If color symbols made sense they would have been adopted a long time ago. They are almost always the wrong approach, too many problems for too little payoff, that's why they are uncommon.
- Dylan16807 3y ago
  Cameras sensors can pick up denser patterns in black and white, especially under imperfect lighting, and the extra data density is not all that much.
- jandrese 3y ago
  Anybody who has tried to color correct for lighting conditions is shaking their head at this idea. Dealing with color is always a headache.
- kccqzy 3y ago
  Humans can't even reliably tell whether a dress is black and blue, or it is white and gold. Color is complicated.

scrollaway 3y ago

Chromatags probably have their uses, but when put in practice like qr codes are, they don't have most of the "features". Monochrome means you can use cheap/shitty printers, you can theme them to go well with your brand, etc.

femto 3y ago

Same reason we use binary computers? The greater noise margin on each bit typically offsets the requirement to have more/smaller/shorter bits compared to a multilevel signal.

nwallin 3y ago

Printing. Printing is done in the CMYK color space. Cyan, Magenta, Yellow, blacK. When you print in color, it is basically four different printers printing onto the same piece of paper. Ideally everything is all lined up correctly, but if you want to do it on an industrial scale, good alignment costs time and money. Big printed color color posters tend to have shitty alignment. A color tag needs to have good alignment; if the cyan, magenta, yellow print runs are misaligned, chances are a color tag won't be able to read it. But the black run is always aligned to the black run. So it will always work. Lighting. The Sun, incandescent, and halogen lights have pretty good color reproduction. But LED lights and fluorescent lights do not. LED lights and fluorescent lights are designed to look acceptable to human eyes. And they can be reasonably good at it. But cameras are not human eyes; color gets all fucky when you look at it through a camera. Cameras. The tag you linked to uses the LAB color space; one channel is brightness, one channel is blue vs yellow, one channel is red vs green. Cameras almost always have BGGR arrays; on a 4 megapixel camera, you will have 1 million blue pixels, 2 million green pixels, and 1 million red pixels. So if you use a normal camera to read a tag in the LAB space, you have 4 million pixels reading the brightness channel, 3 million pixels reading the red-green channel, and 1 million pixels reading the blue-yellow channel.