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#1
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toe and shoulder applied to digital
sensitized photographic film and paper have a toe and shoulder in their
contrast, it is an artifact of chemical activity and exhaustion that just so happens to provide a system to deal with dynamic range, such as highlights and shadows when such chemistry is optimized, and perhaps even before optimized which I don't know the contrast of chemical media, is modeled with rational quadratic and other non-linear but not cubic terms, leaving it to remain within measurement and hybrid systems modeling/engineering ease and simplicity pure digital has gamma, a linear contrast gamma works just fine when the capture, manipulation and output can handle the dynamic range of a scene or artistically created image in a wide enough gamut working space what I glean from the ICC website http"//www.color.org is that output profiles are mapped to the maximal machine code for that device, this means additive systems will have the brightest display, and subtractive systems will have the darkest display, regardless of accuracy, perhaps leaving a linear toe and shoulder from the accurate gamut to the machine maximals this is really not a capture issue, but it is an output and manipulation issue if you used a rational quadratic like Kodak uses for its film and paper contrasts from the region of accurate to machine maximal color, you might deal with highlights and shadows better, it involves a non-linearity in calculation but still a one dimensional look-up table, probably not as applicable to embedded systems which I don't know in the case of ROMM, RIMM, ERIMM, I can see why you might not want to do this to maintain linearity to CIE standards and the end points are not mapped like output devices as far as I know, except with the linearization to ProPhoto RGB which I will address in another post search for ROMM, RIMM, ERIMM and ProPhoto RGB on http://www.color.org and www.wikipedia.org my means are much limited compared to when I worked in Kodak R&D 17 years ago, I can study stuff, but my applications are consumer capture and display pretty much, color manipulation is maturing in GIMP which I no longer have since Redhat uses a version predated color management, and my cell phone is not a smart phone I see clipping of shadows in consumer capture when printed, how printed I don't know I see clipping of highlights on at least television display (I have CRT),, haven't really viewed my LCD computer monitor enough to say there sRGB has failed the consumer use case it wanted, at the expense of some long term development of open systems of color, ProPhoto RGB delivers a centralized system,, but in gamut is not big enough to accommodate digital capture, impending digital display and probably digital projection as I gather, maybe a filter set and associated spectral considerations of sensitivity or density would be a better ROMM, RIMM, ERIMM -- Dale |
#2
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toe and shoulder applied to digital
Dale wrote:
what I glean from the ICC website http"//www.color.org is that output profiles are mapped to the maximal machine code for that device, this means additive systems will have the brightest display, and subtractive systems will have the darkest display, regardless of accuracy, perhaps leaving a linear toe and shoulder from the accurate gamut to the machine maximals This reminds me of a group of very talented old geezers I knew a few decades ago. They were diesel overhaul mechanics who worked on power plants at communications sites. Hence they were often around young telecom technicians, most of whom thought they were pretty significant compared to a mechanic. These guys came up with a few statements that used some of the often heard "key words" comm techs might use. When the mechanics met a tech that they thought might just be a know it all phoney, they'd rattle off a statement just like the one above. Lots of words but with absolutely no sane meaning. If the tech acted as if he understood them, they had one. If he was polite and didn't laugh, that was okay. The best response was someone who broke up laughing and asked who'd taught them to say that. -- Floyd L. Davidson http://www.apaflo.com/ Ukpeagvik (Barrow, Alaska) |
#3
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toe and shoulder applied to digital
High-end digital cameras do not use a simple formula for mapping the CCD
dump into RGB. Each pixel produces around 2^14 levels at ISO 100. When using a very clear lens, a large amount of data beyond the normal black point and white point is captured. The tonal curves can be adjusted and viewed in real-time when post-processing RAW files. In article , Dale wrote: sensitized photographic film and paper have a toe and shoulder in their contrast, it is an artifact of chemical activity and exhaustion that just so happens to provide a system to deal with dynamic range, such as highlights and shadows when such chemistry is optimized, and perhaps even before optimized which I don't know the contrast of chemical media, is modeled with rational quadratic and other non-linear but not cubic terms, leaving it to remain within measurement and hybrid systems modeling/engineering ease and simplicity pure digital has gamma, a linear contrast gamma works just fine when the capture, manipulation and output can handle the dynamic range of a scene or artistically created image in a wide enough gamut working space what I glean from the ICC website http"//www.color.org is that output profiles are mapped to the maximal machine code for that device, this means additive systems will have the brightest display, and subtractive systems will have the darkest display, regardless of accuracy, perhaps leaving a linear toe and shoulder from the accurate gamut to the machine maximals this is really not a capture issue, but it is an output and manipulation issue if you used a rational quadratic like Kodak uses for its film and paper contrasts from the region of accurate to machine maximal color, you might deal with highlights and shadows better, it involves a non-linearity in calculation but still a one dimensional look-up table, probably not as applicable to embedded systems which I don't know in the case of ROMM, RIMM, ERIMM, I can see why you might not want to do this to maintain linearity to CIE standards and the end points are not mapped like output devices as far as I know, except with the linearization to ProPhoto RGB which I will address in another post search for ROMM, RIMM, ERIMM and ProPhoto RGB on http://www.color.org and www.wikipedia.org my means are much limited compared to when I worked in Kodak R&D 17 years ago, I can study stuff, but my applications are consumer capture and display pretty much, color manipulation is maturing in GIMP which I no longer have since Redhat uses a version predated color management, and my cell phone is not a smart phone I see clipping of shadows in consumer capture when printed, how printed I don't know I see clipping of highlights on at least television display (I have CRT),, haven't really viewed my LCD computer monitor enough to say there sRGB has failed the consumer use case it wanted, at the expense of some long term development of open systems of color, ProPhoto RGB delivers a centralized system,, but in gamut is not big enough to accommodate digital capture, impending digital display and probably digital projection as I gather, maybe a filter set and associated spectral considerations of sensitivity or density would be a better ROMM, RIMM, ERIMM |
#4
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toe and shoulder applied to digital
On 02/26/2014 12:07 AM, Floyd L. Davidson wrote:
Dale wrote: what I glean from the ICC website http"//www.color.org is that output profiles are mapped to the maximal machine code for that device, this means additive systems will have the brightest display, and subtractive systems will have the darkest display, regardless of accuracy, perhaps leaving a linear toe and shoulder from the accurate gamut to the machine maximals This reminds me of a group of very talented old geezers I knew a few decades ago. They were diesel overhaul mechanics who worked on power plants at communications sites. Hence they were often around young telecom technicians, most of whom thought they were pretty significant compared to a mechanic. These guys came up with a few statements that used some of the often heard "key words" comm techs might use. When the mechanics met a tech that they thought might just be a know it all phoney, they'd rattle off a statement just like the one above. Lots of words but with absolutely no sane meaning. If the tech acted as if he understood them, they had one. If he was polite and didn't laugh, that was okay. The best response was someone who broke up laughing and asked who'd taught them to say that. I was a systems engineer who was allowed to dabble in science every once in awhile, so yes, I know the buzz words, and had the practical application of systems experience to know a little about applying them, since I only worked 9 years I didn't really become an expert systems engineer, but I think an expert knows what I am getting at my experience at Kodak systems R&D was Imagining Science Training Program 1) first rotation, consumer paper test engineer, 1 year 2) second rotation, consumer C-41 process engineer, I did the beginnings of Flexicolor Stabilizer LF, 1 year 25% of time in classes and a nice little library of books 3) first permanent job, Pro C-41 Process, had some interesting stuff like process variability of new professional films, and a little work on C-41 Q-Lab idea, 2 years 4) second permanent job, Professional Hybrid Systems Integration (I'd like to think I was a little integral in color management), 5 years would have been an interesting job but I was young and caught up in the rat race, in retrospect I could have enjoyed life a lot more then, or at least been financially better off I was a part time Real Estate agent for awhile, I had a two family home and an apartment I rented I almost took a job as a systems engineer on Kodak's Premier PC, a competition to Photoshop, but the funding was not there, and there was overall workflow solution additionally needed found my teenage loves on the streets and crashed and burned, maybe if Rochester wasn't "smug town" thing could have been different pecking orders other than performance, if you want to make a new Kodak stop this -- Dale |
#5
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toe and shoulder applied to digital
On 02/26/2014 12:26 AM, Kevin McMurtrie wrote:
High-end digital cameras do not use a simple formula for mapping the CCD dump into RGB. Each pixel produces around 2^14 levels at ISO 100. When using a very clear lens, a large amount of data beyond the normal black point and white point is captured. The tonal curves can be adjusted and viewed in real-time when post-processing RAW files. never really got the chance to have an expert eye to do such things well, I like a curve I can import -- Dale |
#6
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toe and shoulder applied to digital
On 2014-02-26 05:26:12 +0000, Kevin McMurtrie said:
High-end digital cameras do not use a simple formula for mapping the CCD dump into RGB. Each pixel produces around 2^14 levels at ISO 100. When using a very clear lens, a large amount of data beyond the normal black point and white point is captured. The tonal curves can be adjusted and viewed in real-time when post-processing RAW files. You understand that Dale is very much a troll, with very little to offer the World, don't you? In article , Dale wrote: Bait Snipped -- Regards, Savageduck |
#7
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toe and shoulder applied to digital
On 2/26/2014 1:37 AM, Savageduck wrote:
On 2014-02-26 05:26:12 +0000, Kevin McMurtrie said: High-end digital cameras do not use a simple formula for mapping the CCD dump into RGB. Each pixel produces around 2^14 levels at ISO 100. When using a very clear lens, a large amount of data beyond the normal black point and white point is captured. The tonal curves can be adjusted and viewed in real-time when post-processing RAW files. You understand that Dale is very much a troll, with very little to offer the World, don't you? In article , Dale wrote: Bait Snipped He's one of the few in my killfile. -- PeterN |
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