. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 763 17.9.4 GEGL graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 765 17.9.5 Normal Exposure Exposure defines how much the tool effect will be strong, as a more or less exposed photo- graph. Default slider is 50 but can vary from 0 to 100. 14.4 Transform Tools Figure 14.111 An overview 14.5.7 GEGL Operation Figure 14.184 GEGL Operation tool GEGL (“Generic Graphical Library”) is a graph based image processing library designed to handle var- ious image processing tasks needed in GIMP

a visual graph, a histogram, of the intensity value of the active layer or selection. You can set the threshold range either using the input boxes or clicking button 1 and dragging on the graph. It allows from 0.0 to 1.0. Plot a graph of the settings By clicking on this large button, you can open a window that displays the graph of hue present settings. Figure 15.255: Function graph of present settings Saturation represents green and ‘bb’ represents blue. Histogram In digital image processing, a histogram is a graph representing the statistical frequency of the gray values or the color values in an image. The histogram

– Useful to display a Logarithmic histogram so that values aren’t hidden at the bottom of the graph Colour Levels Display Logarithmic Histogram The middle handle will adjust the midpoint of the

TONAL CORRECTION We have already discussed tonal correction to some extent in the previous para- graph. We mentioned that setting the gamma value to the correct value according to your monitor isn’t always street. To create the drawing, we used the same method that is described in “Transforming A Photo- graph To A Drawing” on page 28. 12. We copied the scanned image into the white background layer, and placed