Where do I fit in the history of data compression?

  • #1

Summary:

Where do I fit in the history of digital image data compression (if at all)? Anybody do it before I did?
In 1982 I was given a ZX Spectrum by a Timex employee. It was one of only three English units that had been converted to NTSC from PAL. They worked for Timex but had their own company on the side to write software for the Timex computer and for the spectrum They hired me to do the title screen artwork for 3 pieces of their software.

This computer was limited. It couldn’t address each pixel separately. It had 4 x 8 pixel character positions that were restricted to two colors each, paper and ink. I had to draw the artwork and then transfer it to a large piece of graph paper coloring every single pixel individually within the constraints. I had to address every pixel position. The file would’ve been huge because the way the computer drew the image on the screen was left to right top to bottom, one pixel at a time.

If I recall correctly the file was a series of one or two numbers separated by commas for each pixel position. To say this was unwieldy is an understatement. It didn’t take me long to figure out going left to right there were consecutive series of numbers where the color and thus the numbers stayed the same because of the artwork. It was then I realized that I didn’t have to address each pixel position for a series of pixels where the color stayed the same I just needed to put in the color and the number of consecutive pixels that had it.

This resulted in compressing the graphic file tremendously. I basically invented a method of digital image data compression. Did anyone do it before I did?
 
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Answers and Replies

  • #2
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It’s likely that you rediscovered a scheme that was already in use On mainframes under a different context like inter-mainframe data communication. When resources are limited, programmers find a way around it.

In the 1960s and 1970s programmers did a lot of tricks that never saw the light of day because code and algorithms were proprietary and weren’t shared, copyrighted or patented.

it wasn’t until the hobbyist micro computer days In the mid 1970s that code sharing became popular in Computer interest groups, magazines and books.

Wikipedia has a brief summary of data compression schemes shown here:

https://en.wikipedia.org/wiki/Data_compression
 
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  • #3
I didn’t think they were doing digital images before personal computers, just software code. I didn’t think mainframe software had graphic cover or title screens back then either. I compressed the file of a digital image it’s not really the same as compressing software.
 
  • #4
Good article Jedi. But it doesn’t have any dates or history. But this was there and it’s almost exactly what I did:

Lossless data compression algorithms usually exploit statistical redundancy to represent data without losing any information, so that the process is reversible. Lossless compression is possible because most real-world data exhibits statistical redundancy. For example, an image may have areas of color that do not change over several pixels; instead of coding "red pixel, red pixel, ..." the data may be encoded as "279 red pixels". This is a basic example of run-length encoding; there are many schemes to reduce file size by eliminating redundancy.”
Wikipedia
 
  • #5
Ibix
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The Run Length Encoding article linked in your quote dates the technique to 1967.
 
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  • #6
Nice article. The 67 date is for television signals not digital. It also states that Hitachi patented it in 1983 for digital images which is after I did it.
 
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  • #7
I found another article and digital images were in use in the 60’s. Somebody probably compressed the data back then.
 
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  • #8
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Sadly, patenting of the technique would have used the RLE example as prior art ie someone invented it in a different context but they did it first. The long strings of repeated characters were found in data communications and screen based data input applications as used on IBM 3270 terminals and other vendors.

I‘ve had ideas that were pretty good like yours but were found to be copies of prior art after a patent search.

Great minds think alike.

I had a boss say that to me once in an attempt to vicariously claim credit when I was a junior programmer and I added the quip and few minds think at all. He caught my drift and I got a Hey.
 
  • #9
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Patenting history is a funny thing. Tesla was screwed out of a patent by Marconi Only to have it reversed years later when the US Govt was paying huge royalties to Marconis company then Tesla ideas were resurrected as prior art.

https://en.wikipedia.org/wiki/Nikola_Tesla

Wireless lawsuits
When World War I broke out, the British cut the transatlantic telegraph cable linking the US to Germany in order to control the flow of information between the two countries. They also tried to shut off German wireless communication to and from the US by having the US Marconi Company sue the German radio company Telefunken for patent infringement.[174] Telefunken brought in the physicists Jonathan Zenneck and Karl Ferdinand Braun for their defense, and hired Tesla as a witness for two years for $1,000 a month. The case stalled and then went moot when the US entered the war against Germany in 1917.[174][175]

In 1915, Tesla attempted to sue the Marconi Company for infringement of his wireless tuning patents. Marconi's initial radio patent had been awarded in the US in 1897, but his 1900 patent submission covering improvements to radio transmission had been rejected several times, before it was finally approved in 1904, on the grounds that it infringed on other existing patents including two 1897 Tesla wireless power tuning patents.[137][176][177] Tesla's 1915 case went nowhere,[178] but in a related case, where the Marconi Company tried to sue the US government over WWI patent infringements, a Supreme Court of the United States 1943 decision restored the prior patents of Oliver Lodge, John Stone, and Tesla.[179] The court declared that their decision had no bearing on Marconi's claim as the first to achieve radio transmission, just that since Marconi's claim to certain patented improvements were questionable, the company could not claim infringement on those same patents.[137][180]
 
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