thebestcpu
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This was my best guess which Forum was best for this post. Please move to a better one if appropriate.
NOTE: This documentation is not needed for the average user. If may be helpful if you need to know the inner workings of Photoshop Blend modes for more scientific. Sometimes, the detailed understanding has allowed me to create Actions/Tools with techniques/tricks from understanding the math behind the blends and more.
The reference document in which this information is contained is the "PDF Reference and Adobe Extensions to the PDF Specification." The information contained in this document is used across many Adobe products, including Photoshop."
https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/pdfreference1.7old.pdf?
The portion about Blends is only 6 pages out of this 1310-page document. I am posting those five pages below. Having the few pages posted below it is easier to find since this PDF document moves around the internet over the years.
Clicking on the images will make them easier to read.
A few comments about the above math as Photoshop has context-dependent or similar terms yet different.
Luminosity in the Luminosity Blend is not the same as the B in Brightness of the HSB model (i.e., the Color Picker) and is not the same as the L in Lightness of the HSL model (used in the HSB/HSL filter)
Saturation Blend is not the same meaning or math as the Saturation used in the Color Picker nor the same as the S Saturation in the HSL model in the HSB / HSL model.
Hue is used consistently in the Blend model, Color picker, and the HSB/HSL filter.
The math is based on RGB or color numbers and is independent of Color Space. Therefore, the actual value of Luminosity, Saturation, and Hue differ for the same visual color of the various color spaces.
Go figure (tongue in cheek
)
John Wheeler
NOTE: This documentation is not needed for the average user. If may be helpful if you need to know the inner workings of Photoshop Blend modes for more scientific. Sometimes, the detailed understanding has allowed me to create Actions/Tools with techniques/tricks from understanding the math behind the blends and more.
The reference document in which this information is contained is the "PDF Reference and Adobe Extensions to the PDF Specification." The information contained in this document is used across many Adobe products, including Photoshop."
https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/pdfreference1.7old.pdf?
The portion about Blends is only 6 pages out of this 1310-page document. I am posting those five pages below. Having the few pages posted below it is easier to find since this PDF document moves around the internet over the years.
Clicking on the images will make them easier to read.
A few comments about the above math as Photoshop has context-dependent or similar terms yet different.
Luminosity in the Luminosity Blend is not the same as the B in Brightness of the HSB model (i.e., the Color Picker) and is not the same as the L in Lightness of the HSL model (used in the HSB/HSL filter)
Saturation Blend is not the same meaning or math as the Saturation used in the Color Picker nor the same as the S Saturation in the HSL model in the HSB / HSL model.
Hue is used consistently in the Blend model, Color picker, and the HSB/HSL filter.
The math is based on RGB or color numbers and is independent of Color Space. Therefore, the actual value of Luminosity, Saturation, and Hue differ for the same visual color of the various color spaces.
Go figure (tongue in cheek
)John Wheeler
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