4.9.2. Invert Reversal
Invert: takes the opposite color value for each point of the current image, as
shown in Fig. 4-35.
Reversal: The color value of each point in the current picture is reversed, and
the formula adopted is PX new = 255 – PX old, as shown in Figure 4-35.
Fig. 4-35 Inverted Reversal Image
4.9.3. Grey Scal GrayScal
changes a color image into a 256-level grey scale image, as shown in Fig. 4-
36. In the state of gray-scale image, the contrast and brightness of the image
can be adjusted to achieve better marking effect.
Fig. 4-36 Grey Scale Marking Image gray processing example
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