Color tab

This tab is used to control the color balance of the preview and scan. It lets you specify the image contrast, brightness, the color balancing, the black and white points and the color space.

Image contrast

You can increase or decrease the overall contrast of the final image by increasing or decreasing this option. Increasing the overall contrast also reduces the apparent brightness of the image.

Before adjusting contrast to change the overall brightness, try experimenting with the brightness option first.

Image brightness

You can multiply the overall intensity by this number to increase or decrease the overall image intensity.

Color balance

Use this option to set the type of color balance you want for each image. If you image is dominated by a single color or bright colors (i.e. flowers or foliage), use the auto levels option, otherwise use the White balance option.

None

- The black and white points aren't used at all, and the image is only corrected for the CCD's color response (if the Correct for option is set to None) or by the film's color response.

Neutral

- Both the black and white points are used to stretch the image's intensity range. However, the relative proportions of red, green, and blue are kept constant.

Tungsten

- Both the black and white points are adjusted to compensate for an image lit by tungsten light (i.e. a normal incandescent light bulb). This removes the reddish cast from indoor pictures taken without a flash.

Fluorescent

- Both the black and white points are adjusted to compensate for an image lit by fluorescent light. This removes the greenish cast from indoor pictures lit by fluorescent lights or lit by flash.

White balance

- VueScan analyzes the image and adjusts it to make the color balance look like the scene is lit by daylight.

Auto levels

- This is a simple mapping of the darkest color to 0.00 intensity and the brightest color to 0.95 intensity.

Black point (%)

The black point is used by the color balance algorithm and is computed by using the histogram of each color in the image. Use this option to leave the black point at the minimum intensity (0%), or to choose the black point such that some percentage of the pixels in the image are below the black point.

Black point red/green/blue

This option lets you set the black point manually. Note that these values are in linear space, not gamma corrected space, so the only practical way to use these values is to do a scan with the "Auto black point" option turned on, then turn it off to lock in these values.

White point (%)

The white point is used by the color balance algorithm and is computed by using the histogram of each color in the image. Use this option to leave the white point at the maximum intensity (0%), or to choose the white point such that some percentage of the pixels in the image are above the white point.

White point red/green/blue

This option lets you set the white point manually. Note that these values are in linear space, not gamma corrected space, so the only practical way to use these values is to do a scan with the "Auto white point" option turned on, then turn it off to lock in these values.

Color space

Use this option to set the color space for the final image. A color space is a combination of color primaries and white point. If you're using Photoshop, you'll probably want to use the Adobe RGB color space, otherwise the sRGB setting is probably best.

If you're using Photoshop, you'll probably also want to enable writing the ICC profile to the TIFF and/or JPEG file by using the TIFF profile and/or JPEG profile option in the Files tab.