Linear gray level transformations include identity and negative transformations. Identity transformation directly maps each pixel value from the input image to the output image, resulting in identical images. Negative transformation inverts each pixel value by subtracting it from the maximum value L-1, effectively inverting the pixel values of the input image. Linear transformations were described along with examples of identity and negative transformations.

1. Gray level transformation

2. Introduction
• There are three basic gray level
transformation.
• Linear
• Logarithmic
• Power – law

3. Cont..
• Linear transformation
• First we will look at the linear transformation.
Linear transformation includes simple identity
and negative transformation.
• Identity transformation has been discussed in
our tutorial of image transformation, but a
brief description of this transformation has
been given here.

4. Cont..
• Identity transition is shown by a straight line.
In this transition, each value of the input
image is directly mapped to each other value
of output image.
• That results in the same input image and
output image.
• And hence is called identity transformation.

5. Linear Transformation

6. Negative transformation
• The second linear transformation is negative
transformation, which is invert of identity
transformation.
• In negative transformation, each value of the
input image is subtracted from the L-1 and
mapped onto the output image.

7. Input Image

8. Output Image

9. Assignment
• Explain linear Transformation with example.