ColorConverter - Input Specifications

The Colorimetric Calculator

Introduction
Conversion flow
Input specifications
Technical specifications

Validate Modes Input

After the Go button is pressed,

a green rectangle indicates a color mode (in this case XYZ) correctly entered;

a pink rectangle indicates an incomplete combination of numbers for this color mode (in this case Lab);

a red rectangle indicates an impossible combination of numbers for this color mode (in this case HSL).

Source RGB Group Modes

For these fields a Range button is available. You can enter values in standard range (H in degrees, R, G, B in 0-255, S, B, L in 0-100) or in a normalized range (all fields in 0-1).

You can enter the following numbers:

• each of R, G and B must be a number between 0 and 255 (standard range) or between 0 and 1 (0-1 range);
• H can be any number, positive or negative, and also 0;
• each of S, B, L must be a number between 0 and 100 (standard range) or between 0 and 1 (0-1 range);

You can also enter only the value of B (of HSB) or L (of HSL) and left H and S fields empty. This is interpreted as an achromatic color, i.e.with H = undefined and S = 0.

The following checks for standard range are implemented (analogous checks are implemented for 0-1 range):

• In the R, G and B field you cannot enter negative values; values greater than 255 are rejected: if you type a value greater than 255 it is replaced with 255;
• In the H fields, any value, positive or negative, or zero, is accepted; the degree symbol is inserted automatically, you don't have to enter it. A value equal or greater than 360° is replaced with an equivalent angular value between 0° and 360° (for example 450° is replaced with 90°, because 90° is equivalent to 450° and is within the accepted range);
• In the S, B, L fields you cannot enter negative values; values greater than 100 are rejected and replaced with 100.

Please note that R, G and B values are independent, i.e. R can be any value independently from G and B and similarly for G e B. However the values H, S and B are not independent. Specifically:

• if S = 0, then H is undefined (this is a gray, i.e. an achromatic color);
• if S > 0, then H must have a definite value between 0° and 360° (this is a chromatic color).

Analogous consideration applies to HSL.

In any case the application tries to intercept any user error and provide a placeholder that appears in each field when the field is empty.

Source XYZ and Lab Group Modes

Each RGB space has their own illuminant, shown in the button on the top, that is is disabled, because the label of this button is the illuminant for the RGB space selected.

Destination Group Modes

All these fields are output only,

ColorConverter is a project by Mauro Boscarol. For information and requests, send an email to me.