Canon PIXMA MG6821 User Manual - Page 766

(Histogram) A histogram allows you to see the data concentration at each brightness level of an image. You can specify the brightest level (highlight) and darkest level (shadow) within an image, cut the levels and expand the middle of the tonal range of the image. Adjusting Histogram (Tone Curve Settings) Adjust the brightness of an image by selecting the type of graph (tone curve) showing the balance of tone input and output. You can make fine adjustments to the brightness of a specific area. Adjusting Tone Curve (Final Review) Make a final check of color adjustments. The final synthesized tone curve and the histogram derived from the subsequent image processing will be displayed. There are no settings to make in this screen. • For a color image, select a color in Channel to check either Red, Green, or Blue, or select Master to check three colors together. • If you place the cursor on the preview image, the portion will be enlarged and its RGB values (only L when Color Mode is Grayscale) before and after the adjustments will be displayed. (Threshold) Set the boundary (threshold) at which black and white are divided. By adjusting the threshold level, you can sharpen text in a document or reduce show-through in newspapers. Setting Threshold Custom You can name and save a set of tone curve and threshold settings of the Color Adjustment Buttons. Select Add/Delete... from the pull-down menu; when Color Mode is set to anything but Black and White, the Add/Delete Tone Curve Settings dialog box opens; when Color Mode is Black and White, the Add/Delete Threshold Settings dialog box opens. 766