White, Black, And Gray-Point Corrections - Konica Minolta IV Instruction Manual

White, gray, and black point corrections
On the tone curve / histogram palette, corrections can be made by specifying a white,
black, and gray point within the image. Locating an appropriate neutral area within the
image is critical to correctly calibrate the software. When the dropper tool is selected,
the RGB display is active and can be used to evaluate the image area. All changes
are immediately reflected in the display image.
Click the white-point button; the mouse
pointer changes to the white dropper
tool.
With the dropper tool, click on the brightest neutral
area of the image to define it as the white point. The
values of the image will be adjusted based on the
selected point. The default level for the white point is
255 for each RGB channel.
Click the black-point button.
With the dropper tool, click on the darkest
neutral area of the image to define it as the black
point. The values of the image will be adjusted based
on the selected point. The default level for the black
point is 0 for each RGB channel.
Click the gray-point button. The grey
point controls the color of the image.
With the dropper tool, click a neutral area of the
image to be defined as the gray point. The area used
to calibrate the gray point must be neutral. The
brightness level of the area is not important, but if the
area has a definite color, the image will not be color
balanced correctly.
Click and hold the apply button to show
the change on the histogram. Click the
reset button to cancel all corrections.
68 A
DVANCED IMAGE PROCESSING