CEC358 Underwater Imaging System Unit 2 part i.pptx

CEC358 Unit II part I Ppt

1. Unit II OPTICAL IMAGE PROCESSING Image Formation, Digitization, Sampling and Quantization, Geometric Transformation, Interpolation, Image Reconstruction, Spatial Filtering, Histogram, Binary Image, Color Fundamentals, Color transformations, Color Interpolation, Morphology, Image segmentation, Pattern Recognition. Challenges involved in underwater optical imaging

2. It describes how pixels are organized in a 2D grid and how their positions correlate to the structure or features within the image.

3. Transforming points means modifying the positions of specific points (or pixels) in the image according to a transformation rule, such as translation, rotation, scaling, etc.

4. An isometry transformation is a type of geometric transformation that preserves distances and angles between points , meaning that the shape and size of an object remain unchanged after the transformation.

5. Key Properties of Isometry Transformations: Distance Preservation : The distance between any two points in the original shape is the same in the transformed shape. Angle Preservation : The angles between any two intersecting lines or edges remain unchanged after transformation. Shape and Size Preservation : Isometry transformations do not change the size or shape of the object being transformed; only its position or orientation is altered. Types of Isometry Transformations: There are several common types of isometries in 2D and 3D geometry: Translation : Moves every point of an object by the same distance in a given direction. Example: Shifting an entire image 5 units to the right. Rotation : Rotates the object around a fixed point (called the center of rotation) by a certain angle, without changing its shape or size. Example: Rotating an image by 90° around its center. Reflection : Flips an object over a line (in 2D) or a plane (in 3D), producing a mirror image of the original shape. Example: Reflecting an object across the y-axis.

6. Similarity transformations are geometric transformations that preserve the shape of an object but may change its size. These transformations include combinations of scaling, translation, rotation, and reflection. Angle Preservation : The angles between lines or points in the original object remain the same after the transformation. Proportional Distance : Distances between points may change, but they are scaled proportionally by a constant factor, meaning the object can grow or shrink uniformly. Shape Preservation : The overall shape of the object remains unchanged, though the object may be larger, smaller, or mirrored.

7. An affine transformation is a type of geometric transformation that preserves points, straight lines, and planes, but not necessarily distances or angles. Key Properties of Affine Transformations: Preserves Parallelism : If two lines are parallel before the transformation, they remain parallel after the transformation. Preserves Straightness : Straight lines remain straight, and flat planes stay flat. Preserves Ratios of Distances : Ratios of distances along a line (such as dividing a line into equal parts) are preserved. Does Not Preserve Angles or Distances : The angles between lines and the lengths of line segments are not necessarily preserved.

8. Key Properties of Projective Transformations: Straight Lines Remain Straight : Like affine transformations, projective transformations preserve straight lines. Parallel Lines May Converge : Parallel lines in the original image may converge to a point after the transformation, simulating perspective effects (like a road disappearing into the horizon). Does Not Preserve Angles or Distances : Unlike isometries or affine transformations, projective transformations do not preserve distances between points or angles between lines. Maps Points at Infinity : In projective geometry, points at infinity (such as where parallel lines would meet) are handled explicitly. This is a key difference from affine transformations, which do not allow such convergence. A projective transformation (also known as a homography or perspective transformation ) is a type of geometric transformation that maps straight lines to straight lines, but does not necessarily preserve parallelism, angles, or distances.

9. Color Fundamentals

10. Color Theory Color theory encompasses the relationships between colors and how they can be combined harmoniously: Primary Colors : Colors that cannot be created by mixing other colors. In additive color theory, these are red, green, and blue; in subtractive color theory, they are cyan, magenta, and yellow. Secondary Colors : Colors created by mixing two primary colors. For example, in the RGB model, mixing red and green creates yellow. Tertiary Colors : Colors formed by mixing a primary color with a secondary color. Color Wheel : A circular diagram that represents the relationships between colors, showing primary, secondary, and tertiary colors.

11. Color Models Different color models define how colors can be represented and mixed: RGB (Red, Green, Blue) : An additive color model used primarily in digital displays. Colors are created by combining different intensities of red, green, and blue light. CMYK (Cyan, Magenta, Yellow, Black) : A subtractive color model used in color printing. It represents colors by mixing different percentages of cyan, magenta, yellow, and black inks. HSV (Hue, Saturation, Value) : A cylindrical color model that describes colors in terms of their hue (color type), saturation (intensity), and value (brightness). It is often used in graphic design and image editing software.