Color Temperature Filter

Accurate Image Manipulation for Desktops

# Color Temperature Filter, 8th Aug 1999

# Description

> Color temperature correction. Place a color sampler into the preview box by:

> > Right-click using the mouse over an area that was gray in the original scene but has a hue in the image.

> Do not choose specular white nor pure black areas, choose an area that should be gray, preferably light gray.

> To change the location of the color sampler repeat right mouse click over an other area.

> > Note: FilterFormula currently provides no way to show instructions to the user. For this reason: If the color sampler is placed over an area that either has fully saturated pixel values (red or green or blue channel is 255) or pixel values that are zero (red or green or blue channel is 0) then the preview window is turned into Red to inform you to select an other area for the probe. (Using such a saturated area would introduce error into the calculation, simply choose another location by right-clicking the preview with the mouse).

# Selection Dropdown, Probe Size.

> Choose the color sampler size, either 3x3, 5x5, 7x7 or 9x9.

# Check Boxes

> 0/255 Inv

> > This is a preview function. When enabled it will give visual feedback for pixels that have channel value 0 or 255. This greatly helps in setting the black-point and white-point accurately. Slowly enable/disable the 0/255 Inv check-box to see the effect.

# Sliders

> BP (Black Point)

> > BP allows to adjust the black-point from level 0 to level 64.

> WP (White Point)

> > WP allows to adjust the white-point to level 255 down to level 64.

# Author

> Timo Autiokari. Homepage: Accurate Image Manipulation for Desktops

# Usage and Distribution Rights

> Free to download and use, distribution is prohibited.

# Filter Engine

> FilterFormula v 1.1, by ATS/Graphics