AZImage help - Detailed help - IP forms - Brightness / contrast

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You are here > Index > Detailed help > Image processing forms > Brightness / contrast



When the auto-exposure system of the camera over-, respectively undercompensates, the resulting image requires a brightness adjustment because it is too bright, respectively too dark. Contrast that is too high/low is usually due to the overall light and shade in the scene.

This tab allows to adjust the brightness and contrast of the picture. The adjustment works on all 3 RGB channels simultaneously. The changes are shown instaneously in the preview area.

The brightness slider sets a negative (to darken) or positive (to brighten) value for the brightness, decreasing or increasing bright tones. It works by adding (respectively substracting) a constant value from each of the RGB values of each pixel, rounding up and down the values. Note that, because of the rounding, information loss may occur in bright areas when increasing the brightness, respectively dark areas when decreasing it.

The contrast slider sets a negative (to decrease) or positive (to increase) value for the contrast. It works by multiplying (respectively dividing) each of the RGB values of all pixels with constant value. Minimal information loss in the picture may occur in extreme cases because resulting values are rounded to the internal 16 bit per channel representation.

Changing the brightness/contrast is an easy way to mess things up as well, so adjust these controls on each of your photograph separately or for multiple shots that have the same lightining and exposure conditions. When used on photos that are taken in different lightning conditions this function will work as expected from the preview for the first photo, but the rest will get less benefits with the same brightness/contrast parameters!

Few tips

An easy way to get the most of your overexposed picture is to slightly increase the contrast while decresing the brightness to compensate for the higher pixel value due to the contrast change (see pictures below).

By overexposed pictures a decrease in the brightness may also do the job, but there is no rule of thumb.



See also >

Image processing main form.