Printing w/ICC profile flattens image too much

[Simon Garrett]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

 

[mike earussi]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

 

[Simon Garrett]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

I don't think that's a correct way to describe it.

A profile is a description of a colour space.

The way colour management works is that a colour-managed programme takes the profile of the image (which describes the image colour space, e.g. sRGB, Adobe RGB etc). It then takes takes the profile of the output device, e.g a monitor, printer or whatever (and the profile describes the colour space of that output device). It uses the two profiles to convert from one colour space to the other. It's nothing really to do with "compensating".

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

I think a colour space definition is more like a metric scale, like measuring a temperature in degrees F or degrees C, or measuring distance in mm or inches. The key difference is that colour space number ranges are limited by definition, typically from 0 to 255.

 

[Euell]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

I don't think that's a correct way to describe it.

A profile is a description of a colour space.

The way colour management works is that a colour-managed programme takes the profile of the image (which describes the image colour space, e.g. sRGB, Adobe RGB etc). It then takes takes the profile of the output device, e.g a monitor, printer or whatever (and the profile describes the colour space of that output device). It uses the two profiles to convert from one colour space to the other. It's nothing really to do with "compensating".

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

I think a colour space definition is more like a metric scale, like measuring a temperature in degrees F or degrees C, or measuring distance in mm or inches. The key difference is that colour space number ranges are limited by definition, typically from 0 to 255.

ICC profiles describe the color attributes of the printer by defining a mapping between the computer file and the printer. Color space defines the colors (gamut) that are included in the particular color space. Color space is not measured from 0-255, which instead refers to the relative intensity of the red, green or blue (RGB) color channel.

 

[Ken60]

Seems we have a large cross match of a profile and a colour space.

I think we have to imagine a colour space ( sRGB or aRGB ) as a cupboard, the larger the cupboard the easier it is to fit large images into it without the sleeves or tails catching on the sides or bottom and creasing. Rendering intent is rather like deciding how the bits that are too big to fit into the cupboard are folded to avoid creasing. Picture the three dimensional space withing a huge free standing cupboard, and consider it as allocated space by a matrix of x, y and z axis.

Now we have an object to hang in that space in a uniform and predictable way. If we give the object its own location identity and match that to the matrix given to the cupboard, its location within that space is both accurate and predictable, how much space surrounds it depends on the size of the object and if it reaches the edges of the space. A small object ( sRGB image) hanging in a large (Rec 2020 ) cupboard will swing untouched by its surroundings . The other way round , an aRGB object hanging in a sRGB space will require the saturated areas that are out of the spaces holding to be folded in such a way as not to exceed its space ( out of gamut handling based on rendering intent)

So now we have to take this beautifully placed object from our carefully planned cupboard , and go with it on holiday to another place. How can we ensure that it will hang so correctly in the next space, not creasing on the sides in a squash. Obviously if the owner of the place we are visiting has the same plan for their cupboard our object will hang perfectly as it did at home..... however life is never easy, their floor is uneven and leans to the left, meaning with gravity our object will touch the sides even though both cupboards have the same space inside. So now we measure the difference between the angle of the space in the holiday cupboard and build a change log of coordinates. Now the object hangs in the holiday space , as it hung at home.... the coordinates have changed or been translated to the new space ( icc profile ) but the object is unchanged in it relationship to its planned environment and has the same size as it always had ( gamut).

Now if every cupboard in Chrisindon had a similar plan given to them , our problems would be just producing a translation ( icc profile) for each and every cupboard used and our hanging nightmares are over for ever.

If an object is planned to fit into an aRGB space , this does not mean its colours have all of the colours of that space, it just means it is planned so that it will hang perfectly in that space. Planning the same object to hang in a Profoto space does not give it more colours, it just means it hangs with more spare room around it .

 

[Simon Garrett]

Seems we have a large cross match of a profile and a colour space.

A profile describes a colour space, usually in terms of CIELAB or CIEXYZ profile connection spaces.

I think we have to imagine a colour space ( sRGB or aRGB ) as a cupboard, the larger the cupboard the easier it is to fit large images into it without the sleeves or tails catching on the sides or bottom and creasing. Rendering intent is rather like deciding how the bits that are too big to fit into the cupboard are folded to avoid creasing. Picture the three dimensional space withing a huge free standing cupboard, and consider it as allocated space by a matrix of x, y and z axis.

Now we have an object to hang in that space in a uniform and predictable way. If we give the object its own location identity and match that to the matrix given to the cupboard, its location within that space is both accurate and predictable, how much space surrounds it depends on the size of the object and if it reaches the edges of the space. A small object ( sRGB image) hanging in a large (Rec 2020 ) cupboard will swing untouched by its surroundings . The other way round , an aRGB object hanging in a sRGB space will require the saturated areas that are out of the spaces holding to be folded in such a way as not to exceed its space ( out of gamut handling based on rendering intent)

So now we have to take this beautifully placed object from our carefully planned cupboard , and go with it on holiday to another place. How can we ensure that it will hang so correctly in the next space, not creasing on the sides in a squash. Obviously if the owner of the place we are visiting has the same plan for their cupboard our object will hang perfectly as it did at home..... however life is never easy, their floor is uneven and leans to the left, meaning with gravity our object will touch the sides even though both cupboards have the same space inside. So now we measure the difference between the angle of the space in the holiday cupboard and build a change log of coordinates. Now the object hangs in the holiday space , as it hung at home.... the coordinates have changed or been translated to the new space ( icc profile ) but the object is unchanged in it relationship to its planned environment and has the same size as it always had ( gamut).

Now if every cupboard in Chrisindon had a similar plan given to them , our problems would be just producing a translation ( icc profile) for each and every cupboard used and our hanging nightmares are over for ever.

If an object is planned to fit into an aRGB space , this does not mean its colours have all of the colours of that space, it just means it is planned so that it will hang perfectly in that space. Planning the same object to hang in a Profoto space does not give it more colours, it just means it hangs with more spare room around it .

This cupboard thing sounds a bit complicated! I view it more simply. Some colour spaces encompass a larger gamut than others. As a result, mapping from a larger one to a smaller one results in colours that can't be directly mapped. This is where rendering intent comes in, to determine what to do with colours that don't map, and how to compensate (if necessary) with other colours.

 

[Simon Garrett]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

I don't think that's a correct way to describe it.

A profile is a description of a colour space.

The way colour management works is that a colour-managed programme takes the profile of the image (which describes the image colour space, e.g. sRGB, Adobe RGB etc). It then takes takes the profile of the output device, e.g a monitor, printer or whatever (and the profile describes the colour space of that output device). It uses the two profiles to convert from one colour space to the other. It's nothing really to do with "compensating".

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

I think a colour space definition is more like a metric scale, like measuring a temperature in degrees F or degrees C, or measuring distance in mm or inches. The key difference is that colour space number ranges are limited by definition, typically from 0 to 255.

ICC profiles describe the color attributes of the printer by defining a mapping between the computer file and the printer.

Not quite. An ICC profile describes the mapping between the colour space described in that profile an and ICC Profile Connection Space, usually CIELAB or CIEXYZ. This is the same whether the profile describes the colour space of a physical device such as a printer or monitor, or whether the profile describes a standard virtual device, such as sRGB or Adobe RGB.

In order to colour manage an image from a file to a device, two profiles are involved. One is the profile that describes the colour space of the image (e.g. sRGB or Adobe RGB) and the other is the profile for the device. A colour managed program will normally convert the image from the source colour space (e.g. sRGB etc) via a Profile Connection Space, to the device colour space.

Color space defines the colors (gamut) that are included in the particular color space. Color space is not measured from 0-255, which instead refers to the relative intensity of the red, green or blue (RGB) color channel.

A profile describes a range of colours that can be represented in terms of one of the ICC PCSs, and also describes such matters as white point and Tone Response Curve (TRC).

--
Simon

 

[Vernon D Rainwater]

I read every post. 16 bit was mentioned more than once. What "Home use printers" have the capability to print using 16 bit (without first converting to 8 bit).

I don't use outside printing service or I would ask the sane for those printers.

 

[gscotten]

I read every post. 16 bit was mentioned more than once. What "Home use printers" have the capability to print using 16 bit (without first converting to 8 bit).

I don't use outside printing service or I would ask the sane for those printers.

I believe all the Pro series printers (Pro-10, Pro-100, etc) have a 16 bit XPS driver. What happens inside the printer is anybody's guess. I don't see any difference in my prints using either driver, but always use the 16 bit XPS driver just in case.

 

[Ken60]

Regardless of the arguments re seeing the difference of 16 bit print, it makes huge sense as it allows the image to be returned to photoshop , as is , and corrections or adjustments made in the original 16 bit format. Change to 8 for print and you are quite limited.

 

[Simon Garrett]

Regardless of the arguments re seeing the difference of 16 bit print, it makes huge sense as it allows the image to be returned to photoshop , as is , and corrections or adjustments made in the original 16 bit format. Change to 8 for print and you are quite limited.

Good point.

Additionally, I suggest try to minimise conversions of colour space. For example, if you use Lightroom then Lightroom's Develop Module always uses ProPhoto RGB (with a linerar TRC) for its working space, so if sending images to Photoshop for further editing, it makes sense to use ProPhoto RGB as the working space in Photoshop.

 

[Euell]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

I don't think that's a correct way to describe it.

A profile is a description of a colour space.

The way colour management works is that a colour-managed programme takes the profile of the image (which describes the image colour space, e.g. sRGB, Adobe RGB etc). It then takes takes the profile of the output device, e.g a monitor, printer or whatever (and the profile describes the colour space of that output device). It uses the two profiles to convert from one colour space to the other. It's nothing really to do with "compensating".

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

I think a colour space definition is more like a metric scale, like measuring a temperature in degrees F or degrees C, or measuring distance in mm or inches. The key difference is that colour space number ranges are limited by definition, typically from 0 to 255.

ICC profiles describe the color attributes of the printer by defining a mapping between the computer file and the printer.

Not quite. An ICC profile describes the mapping between the colour space described in that profile an and ICC Profile Connection Space, usually CIELAB or CIEXYZ. This is the same whether the profile describes the colour space of a physical device such as a printer or monitor, or whether the profile describes a standard virtual device, such as sRGB or Adobe RGB.

This definition is both abstruse functionally bereft. A printer is, of course, perfectly capable of printing a photo file without the use of an external ICC profile. So what is the capability of an added ICC profile ? The ICC profile is necessary for more precise color on the print MEDIA USED, which is why we have different ICC profiles for different media.

The color space is an attribute of the photo file, not the ICC profile, which will accommodate whatever color space exists in the file. Of course, it does not follow that all colors that may exist in the file can be replicated precisely by the target printer. Your jobbed Wikipedia definition is nothing if not confusing.

In order to colour manage an image from a file to a device, two profiles are involved. One is the profile that describes the colour space of the image (e.g. sRGB or Adobe RGB) and the other is the profile for the device. A colour managed program will normally convert the image from the source colour space (e.g. sRGB etc) via a Profile Connection Space, to the device colour space.

There are certainly more RGB color spaces than sRGB and Adobe RGB. ProfotoRGB, for example, but there are several others that have been used for photographic reproduction as well. These color spaces are an attribute of the photo file, not the ICC profile, which merely adjusts color to more precisely reproduce the photo file on the selected media.

Color space defines the colors (gamut) that are included in the particular color space. Color space is not measured from 0-255, which instead refers to the relative intensity of the red, green or blue (RGB) color channel.

A profile describes a range of colours that can be represented in terms of one of the ICC PCSs, and also describes such matters as white point and Tone Response Curve (TRC).

Yes, colors are created by combinations of the red, green and blue color channels, the ratio of which determines the color produced, and the intensity of each RGB color channel is measured on a scale of 0-255.

 

[Simon Garrett]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

I don't think that's a correct way to describe it.

A profile is a description of a colour space.

The way colour management works is that a colour-managed programme takes the profile of the image (which describes the image colour space, e.g. sRGB, Adobe RGB etc). It then takes takes the profile of the output device, e.g a monitor, printer or whatever (and the profile describes the colour space of that output device). It uses the two profiles to convert from one colour space to the other. It's nothing really to do with "compensating".

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

I think a colour space definition is more like a metric scale, like measuring a temperature in degrees F or degrees C, or measuring distance in mm or inches. The key difference is that colour space number ranges are limited by definition, typically from 0 to 255.

ICC profiles describe the color attributes of the printer by defining a mapping between the computer file and the printer.

Not quite. An ICC profile describes the mapping between the colour space described in that profile an and ICC Profile Connection Space, usually CIELAB or CIEXYZ. This is the same whether the profile describes the colour space of a physical device such as a printer or monitor, or whether the profile describes a standard virtual device, such as sRGB or Adobe RGB.

This definition is both abstruse functionally bereft. A printer is, of course, perfectly capable of printing a photo file without the use of an external ICC profile. So what is the capability of an added ICC profile ?

Most printers by default will guess that the image is sRGB, and know the characteristics of the printer with the paper that's been set, so will do their own colour management, effectively with built-in profiles. However, most don't aim for accurate coloour, but "pleasing colour", which is often not the same. Hence use of ICC profiles (two of them: one for the image and one for the printer) will often enable more accurate colour rendition on the printer than by using built-in colour rendition.

The ICC profile is necessary for more precise color on the print MEDIA USED, which is why we have different ICC profiles for different media.

The color space is an attribute of the photo file, not the ICC profile, which will accommodate whatever color space exists in the file. Of course, it does not follow that all colors that may exist in the file can be replicated precisely by the target printer. Your jobbed Wikipedia definition is nothing if not confusing.

In order to colour manage an image from a file to a device, two profiles are involved. One is the profile that describes the colour space of the image (e.g. sRGB or Adobe RGB) and the other is the profile for the device. A colour managed program will normally convert the image from the source colour space (e.g. sRGB etc) via a Profile Connection Space, to the device colour space.

There are certainly more RGB color spaces than sRGB and Adobe RGB. ProfotoRGB, for example, but there are several others that have been used for photographic reproduction as well. These color spaces are an attribute of the photo file,

more precisely, the image in the file

not the ICC profile, which merely adjusts color to more precisely reproduce the photo file on the selected media.

This isn't right. The profile describes a colour space. It doesn't adjust colour, it doesn't change anything, it doesn't tell you how to change anything. It's a static description of a colour space.

It's the colour managed program that adjusts the numerical RGB data, based on the information in the image profile and the printer profile.

Color space defines the colors (gamut) that are included in the particular color space. Color space is not measured from 0-255, which instead refers to the relative intensity of the red, green or blue (RGB) color channel.

A profile describes a range of colours that can be represented in terms of one of the ICC PCSs, and also describes such matters as white point and Tone Response Curve (TRC).

Yes, colors are created by combinations of the red, green and blue color channels, the ratio of which determines the color produced, and the intensity of each RGB color channel is measured on a scale of 0-255.

 

[Euell]

I always send to print in aRB or Pro Photo and 16 bits on the desktop, the icc is a correction profile to match a piece of equipment, NOT a colour profile.

Can you explain that please?

To my understanding, an ICC profile is a colour profile, whether it's a profile for a specific device, or a standard profile such as sRGB, Adobe RGB or ProPhoto RGB.

I'm not sure what you mean by a "correction profile". Again, to my understanding, an ICC profile describes a colour space of a real or virtual device.

Perhaps we mean the same thing, and it's just terminology?

"What you see is what you get" is the goal of color management. To that end an ICC profile is created to compensate for the printer, ink and paper used so it will look correct on a color corrected monitor and in the print.

I don't think that's a correct way to describe it.

A profile is a description of a colour space.

The way colour management works is that a colour-managed programme takes the profile of the image (which describes the image colour space, e.g. sRGB, Adobe RGB etc). It then takes takes the profile of the output device, e.g a monitor, printer or whatever (and the profile describes the colour space of that output device). It uses the two profiles to convert from one colour space to the other. It's nothing really to do with "compensating".

sRGB, Adobe RGB and Pro Photo RGB are the most common color spaces used in photography with the latter being the highest quality. This color space setting tells the printer how many "colors" can be used in the final print (it's actually more about color saturation or intensity than the actual color and is called Gamut). The space used is determined by the photographer and is chosen when the raw file is processed and saved usually as a jpeg or tiff.

I think a colour space definition is more like a metric scale, like measuring a temperature in degrees F or degrees C, or measuring distance in mm or inches. The key difference is that colour space number ranges are limited by definition, typically from 0 to 255.

ICC profiles describe the color attributes of the printer by defining a mapping between the computer file and the printer.

Not quite. An ICC profile describes the mapping between the colour space described in that profile an and ICC Profile Connection Space, usually CIELAB or CIEXYZ. This is the same whether the profile describes the colour space of a physical device such as a printer or monitor, or whether the profile describes a standard virtual device, such as sRGB or Adobe RGB.

This definition is both abstruse functionally bereft. A printer is, of course, perfectly capable of printing a photo file without the use of an external ICC profile. So what is the capability of an added ICC profile ?

Most printers by default will guess that the image is sRGB, and know the characteristics of the printer with the paper that's been set, so will do their own colour management, effectively with built-in profiles. However, most don't aim for accurate coloour, but "pleasing colour", which is often not the same. Hence use of ICC profiles (two of them: one for the image and one for the printer) will often enable more accurate colour rendition on the printer than by using built-in colour rendition.

The printer doesn't "guess" a color space and doesn't need to know the color space in which an image file is saved, nor is it necessary to establish a particular color space with regard to an image file. A printer cannot establish "accurate" color for a particular paper/media, unless an ICC profile for that paper is used with the printer software. Color can be managed by the computer software or by the printer. Obviously, if color is managed by the printer, the color management is standard in response to the color information sent by the printer driver. Color management by the computer software may or may not reflect a particular color space and need not utilize an ICC profile specific to the print media/paper.

The ICC profile is necessary for more precise color on the print MEDIA USED, which is why we have different ICC profiles for different media.

The color space is an attribute of the photo file, not the ICC profile, which will accommodate whatever color space exists in the file. Of course, it does not follow that all colors that may exist in the file can be replicated precisely by the target printer. Your jobbed Wikipedia definition is nothing if not confusing.

In order to colour manage an image from a file to a device, two profiles are involved. One is the profile that describes the colour space of the image (e.g. sRGB or Adobe RGB) and the other is the profile for the device. A colour managed program will normally convert the image from the source colour space (e.g. sRGB etc) via a Profile Connection Space, to the device colour space.

There are certainly more RGB color spaces than sRGB and Adobe RGB. ProfotoRGB, for example, but there are several others that have been used for photographic reproduction as well. These color spaces are an attribute of the photo file,

more precisely, the image in the file

not the ICC profile, which merely adjusts color to more precisely reproduce the photo file on the selected media.

This isn't right. The profile describes a colour space. It doesn't adjust colour, it doesn't change anything, it doesn't tell you how to change anything. It's a static description of a colour space.

Not so. A color space, such as sGRB, the most limited usual color space, simply defines the total hues within that color space. The ICC profile for a particular paper, on the other hand, describes how the printer is to adjust the color balance, so as to reproduce/print those colors in nearest conformity to the image file on the paper for which the ICC profile was determined.

It's the colour managed program that adjusts the numerical RGB data, based on the information in the image profile and the printer profile.

Color space defines the colors (gamut) that are included in the particular color space. Color space is not measured from 0-255, which instead refers to the relative intensity of the red, green or blue (RGB) color channel.

A profile describes a range of colours that can be represented in terms of one of the ICC PCSs, and also describes such matters as white point and Tone Response Curve (TRC).

Yes, colors are created by combinations of the red, green and blue color channels, the ratio of which determines the color produced, and the intensity of each RGB color channel is measured on a scale of 0-255.

 

[Euell]

Seems we have a large cross match of a profile and a colour space.

A profile describes a colour space, usually in terms of CIELAB or CIEXYZ profile connection spaces.

I think we have to imagine a colour space ( sRGB or aRGB ) as a cupboard, the larger the cupboard the easier it is to fit large images into it without the sleeves or tails catching on the sides or bottom and creasing. Rendering intent is rather like deciding how the bits that are too big to fit into the cupboard are folded to avoid creasing. Picture the three dimensional space withing a huge free standing cupboard, and consider it as allocated space by a matrix of x, y and z axis.

Now we have an object to hang in that space in a uniform and predictable way. If we give the object its own location identity and match that to the matrix given to the cupboard, its location within that space is both accurate and predictable, how much space surrounds it depends on the size of the object and if it reaches the edges of the space. A small object ( sRGB image) hanging in a large (Rec 2020 ) cupboard will swing untouched by its surroundings . The other way round , an aRGB object hanging in a sRGB space will require the saturated areas that are out of the spaces holding to be folded in such a way as not to exceed its space ( out of gamut handling based on rendering intent)

So now we have to take this beautifully placed object from our carefully planned cupboard , and go with it on holiday to another place. How can we ensure that it will hang so correctly in the next space, not creasing on the sides in a squash. Obviously if the owner of the place we are visiting has the same plan for their cupboard our object will hang perfectly as it did at home..... however life is never easy, their floor is uneven and leans to the left, meaning with gravity our object will touch the sides even though both cupboards have the same space inside. So now we measure the difference between the angle of the space in the holiday cupboard and build a change log of coordinates. Now the object hangs in the holiday space , as it hung at home.... the coordinates have changed or been translated to the new space ( icc profile ) but the object is unchanged in it relationship to its planned environment and has the same size as it always had ( gamut).

Now if every cupboard in Chrisindon had a similar plan given to them , our problems would be just producing a translation ( icc profile) for each and every cupboard used and our hanging nightmares are over for ever.

If an object is planned to fit into an aRGB space , this does not mean its colours have all of the colours of that space, it just means it is planned so that it will hang perfectly in that space. Planning the same object to hang in a Profoto space does not give it more colours, it just means it hangs with more spare room around it .

This cupboard thing sounds a bit complicated! I view it more simply. Some colour spaces encompass a larger gamut than others. As a result, mapping from a larger one to a smaller one results in colours that can't be directly mapped. This is where rendering intent comes in, to determine what to do with colours that don't map, and how to compensate (if necessary) with other colours.

Put even more simply with respect to the two most commonly used rendering intents: perceptual rendering intent changes ALL the colors, not just those out of gamut, to maintain the relationships between the colors. In contrast, relative colorimetric rendering intent reassigns out-of-gamut colors only.

 

[Ken60]

Simon the only proviso I would put to your explanations to save confusion, is that a colour space like aRGB , can have no numerical data stored in it . Hence my comments re a cupboard. It is purely a mapping of a three dimensional space, with aRGB mapping a larger space than sRGB. When an image is placed in this vacant space it is placed to match the colour mapping so that all can read it with ease, and if it contains more colours than the space is mapped for , then rendering intent controls how the colours are adjusted to fit.

An icc profile for a printing paper contains data that takes an aRGB mapped image data and adjusts this data to match the mapping of a screen or printer etc. You control an image with an icc profile.

 

[Simon Garrett]

Simon the only proviso I would put to your explanations to save confusion, is that a colour space like aRGB , can have no numerical data stored in it . Hence my comments re a cupboard. It is purely a mapping of a three dimensional space, with aRGB mapping a larger space than sRGB. When an image is placed in this vacant space it is placed to match the colour mapping so that all can read it with ease, and if it contains more colours than the space is mapped for , then rendering intent controls how the colours are adjusted to fit.

An icc profile for a printing paper contains data that takes an aRGB mapped image data and adjusts this data to match the mapping of a screen or printer etc. You control an image with an icc profile.

Agreed. I would prefer to say that a profile doesn't adjust the data, but the colour-managed program uses the image profile and the device profile to adjust the data, but I guess it comes to the same thing.

 

[Simon Garrett]

Seems we have a large cross match of a profile and a colour space.

A profile describes a colour space, usually in terms of CIELAB or CIEXYZ profile connection spaces.

I think we have to imagine a colour space ( sRGB or aRGB ) as a cupboard, the larger the cupboard the easier it is to fit large images into it without the sleeves or tails catching on the sides or bottom and creasing. Rendering intent is rather like deciding how the bits that are too big to fit into the cupboard are folded to avoid creasing. Picture the three dimensional space withing a huge free standing cupboard, and consider it as allocated space by a matrix of x, y and z axis.

Now we have an object to hang in that space in a uniform and predictable way. If we give the object its own location identity and match that to the matrix given to the cupboard, its location within that space is both accurate and predictable, how much space surrounds it depends on the size of the object and if it reaches the edges of the space. A small object ( sRGB image) hanging in a large (Rec 2020 ) cupboard will swing untouched by its surroundings . The other way round , an aRGB object hanging in a sRGB space will require the saturated areas that are out of the spaces holding to be folded in such a way as not to exceed its space ( out of gamut handling based on rendering intent)

So now we have to take this beautifully placed object from our carefully planned cupboard , and go with it on holiday to another place. How can we ensure that it will hang so correctly in the next space, not creasing on the sides in a squash. Obviously if the owner of the place we are visiting has the same plan for their cupboard our object will hang perfectly as it did at home..... however life is never easy, their floor is uneven and leans to the left, meaning with gravity our object will touch the sides even though both cupboards have the same space inside. So now we measure the difference between the angle of the space in the holiday cupboard and build a change log of coordinates. Now the object hangs in the holiday space , as it hung at home.... the coordinates have changed or been translated to the new space ( icc profile ) but the object is unchanged in it relationship to its planned environment and has the same size as it always had ( gamut).

Now if every cupboard in Chrisindon had a similar plan given to them , our problems would be just producing a translation ( icc profile) for each and every cupboard used and our hanging nightmares are over for ever.

If an object is planned to fit into an aRGB space , this does not mean its colours have all of the colours of that space, it just means it is planned so that it will hang perfectly in that space. Planning the same object to hang in a Profoto space does not give it more colours, it just means it hangs with more spare room around it .

This cupboard thing sounds a bit complicated! I view it more simply. Some colour spaces encompass a larger gamut than others. As a result, mapping from a larger one to a smaller one results in colours that can't be directly mapped. This is where rendering intent comes in, to determine what to do with colours that don't map, and how to compensate (if necessary) with other colours.

Put even more simply with respect to the two most commonly used rendering intents: perceptual rendering intent changes ALL the colors, not just those out of gamut, to maintain the relationships between the colors. In contrast, relative colorimetric rendering intent reassigns out-of-gamut colors only.

Agree with all that.

 

[CatchingTime]

One last thing I just learned. I may have been using the ICC profile wrong.

from the other forum the comment was “I know nothing about their specific profile, but usually you soft proof by enabling the profile in your raw converter, and then make the color corrections to the file based upon how the ICC profile affected it. Then, submit as you normally would, using sRGB or AdobeRGB as the embedded profile (in other words, don’t embed the printer profile itself).

I was setup for the ICC profile for viewing/soft proofing, but would also, embed the printer profile itself for output. I’ll be very interred in how prints will look going forward. It’s funny, all the Capture One videos I watched never really got into the details or change needed for output for print. Most concentrated on how to setup the soft proof view….

You're welcome.

 

[CatchingTime]

Look at Bay Photo's web site. They offer a lot of options in different price points. I'm not saying you should use them, but if you thoroughly look through their site you'll have a much better idea of all the options that are available in the market.

https://www.bayphoto.com/

Bay is one of the labs who has a single ICC profile for all available substrates. I do not understand how that can possibly work with the wide variety of papers available, but perhaps they internally soft-proof in an automated way (assuming you select 'Color Correction'). That being said, I also use WHCC who has a profile for nearly every paper they use, and in general the output from each lab has been similarly consistent.

I've had more problems with both labs since COVID than in the ten years prior. But, they do stand by their product and replace prints when appropriate.

--
My $0.02 in a world where pennies are obsolete.