Quad trees are tree data structures used to efficiently store and manage point data in two-dimensional space, particularly useful in applications involving large quantities of precise data like digital maps. They break down information into smaller chunks, which aids in tasks such as image compression and searching for locations. However, quad trees have limitations in comparing images that differ in rotation due to their distinct structural representations.

1. QUAD TREES
From Pixels to Places :
Harnessing the Power of
Quad Trees

2. Our Team
PRN Name Roll no.
22211574 Sudhanshu Lacca 231036
22210151 Piyush Nikam 231044
22211018 Gautam Nimase 231046
22211434 Anuj Padhar 231048

3. What are QUAD trees ?
A Quad-Tree is a tree data structure in which each internal
node has exactly four children.

4. Abstract
1) Many digital map applications have the need to present large
quantities of precise point data on the map. Such data can be
weather information, the population in towns, etc.
2) With the advancements in data science/ML, we expect such data
will grow at a rapid pace. How to visualize such magnitude of data
becomes a problem.
3) QuadTree is a data structure in which each internal node has
exactly four children.
4) Quadtrees are trees implemented to efficiently store data of points
on a two-dimensional space.

11. 1) Given : n * n matrix grid of
0's and 1's only. We want to
represent grid with a Quad-
Tree.
Example(s)

12. 1) All values in the grid are not the same. We divide the grid into
four sub-grids.
2) The topLeft, bottomLeft and bottomRight each has the same
value.
3) The topRight have different values so we divide it into 4 sub-
grids where each has the same value.

13. Pseudocode

14. and applications

16. Super Mario
Quad trees can handle sparse Mario
level a billion times across, where one
tile contains the finishing spot. A Quad
tree will split the arrival spot into
different cells and still use gigantic cells
for the empty spaces.

17. Limitation
1) The fundamental drawback of the Quad
Tree is comparing two pictures that vary
only in rotations or translations is
difficult.
2) This is due to the fact that the Quad Tree
depiction of such pictures will be so
distinct.
3) The pictures rotation methods offered
are limited to revolutions of 90 degrees.
4) As we can see, it is not possible to
compare two images that are different in
terms of rotation.

18. Literature Survey

19. Conclusion
Quad trees are like a puzzle where each piece represents a
small part of a bigger picture. They help organize
information, such as images or maps, by breaking them
down into smaller chunks. This makes it easier to find and
work with specific areas or details. Quad trees are handy for
tasks like compressing images or finding nearby locations on
a map.

20. References :
Research papers :
1) https://www.researchgate.net/publication/220197855_Quad_Trees_A_Data_Structure_
for_Retrieval_on_Composite_Keys
2) chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/
https://people.scs.carleton.ca/~maheshwa/courses/5703COMP/16Fall/quadtrees-pap
er.pdf
https://blog.bytebytego.com/p/how-quadtree-works
https://www.educative.io/answers/what-is-a-quadtree-how-is-it-used-in-location-based-ser
vices
https://leetcode.com/problems/construct-quad-tree/description/

21. Thank
You !!