Running digital images of black and white snaps of paper stock and want to use software to determine two measurements "Paper Brightness and Paper Whiteness". Needing images bulk loaded into the program and for images to be measured and reported on automatically. Need to remember the file name of the image and then append a PB code (PB + number value) and a PW code (PW + number value). The following are the definitions of Paper Brightness Versus Paper Whiteness:
Paper brightness versus paper whiteness can be compared through the measure of light. Paper brightness refers to the papers ability to reflect light while paper whiteness refers to the quality of light -that is, the shade of the paper. What is Paper Brightness?
The general understanding of brightness is the amount of light reflectance, usually based on a scale of 0-100%. The higher the number, the more “bright” a sheet is or that is to say, the higher amount of reflectance of blue light refers to the brightness of a sheet of paper. For example, paper with a higher measurement on the scale will reflect more blue light than a sheet of paper measuring less on the scale. This light reflectance is measured against specific wavelengths as opposed to all wavelengths of light like whiteness.
Within the industry, there are 3 standards that measure paper brightness. Each standard uses different techniques and different equipment to achieve their brightness result and measurements are not interchangeable with one another.
TAPPI/G.E Brightness: The North American standard that measures the brightness of paper as visible in an environment consisting of a mixture of cool-white fluorescent and some filtered daylight. The light will only hit the sheet of paper from one angle which means that this standard will always be lower than other standards. The UV of TAPPI brightness is also the lowest of all the measuring standards.
ISO Brightness: ISO brightness is a European measuring standard that measures brightness in an environment with cool-white fluorescent and some unfiltered daylight. The light will hit the sample sheet from all different angles. Measurements can exceed 100% but not by a significant amount. Paper samples with the more fluorescent present will likely measure higher in brightness on the ISO scale compared with TAPPI.
D65 Brightness: This measurement uses outdoor light because of the levels of UV present to interact with the fluorescent in the paper. Considering this, brightness levels can easily record over 100% making D65 scales much higher than TAPPI and ISO.
What is Paper Whiteness?
Paper whiteness refers to the amount of red, blue, and green reflectance that the eye can see when looking at a sheet of paper. Paper whiteness can be warm white if reflectance comprises of more reds; and cool white if it consists of more blues. The environment in which you view the sheet of paper will affect the amount of whiteness visible. In attempting to achieve more whiteness, OBAs (optical brightening agents) are added to a duller sheet of paper. In outdoor lighting, this sheet will appear much whiter than when viewing it indoors. The reverse applies. A sheet of paper that has an appropriate white base and low levels of OBAs will appear whiter indoors and duller outdoors. It is then fair to say that using different types of paper for one document may affect the aesthetics and quality of the final product, depending on when/where the document will be viewed.