Final report : Part 3

The filters I tested out generated some results that help in preparing a document for OCR.
In a tabular format, the results look like :

	Median Filter	Gaussian Filters	Greyscale Conversion	Bilateral Filters	Adaptive Thresholding	Resolution Changes	WhiteWashing Algo
Color Images	G	R	G	G	G	N,A	Works as intended
NewsPaper	R	G	G	G	R, S	N,A	Works as intended
Books	R	G	G	G	R, S	N,A	Works as intended
Posters	G	N, A	G	G	G, S	N,A	Works as intended

Legend :
R : Recommended
G : Good Results, Useful to have
N : Neutral
A : Adverse Effects
S : improved results with Whitewashing

Explanations :

All tests were performed on random image samples found via a basic image search on Google.
NOTE : Tests mentioned in Column N should be performed before tests in column N+1. 

Median Filters:
These are useful for Color Images, and seem to improve the output in general for all documents.
In case of samples from newspapers and books, they helped greatly in removing noise.

Gaussian Smoothing:
It helped in smoothing the images before greyscale conversion, but in case of Posters, the smoothing often distorted the text as well.

Greyscale Conversion :
It is always better to do a greyscale conversion as there is no downside to it.
Often, using a filter to "skeletonize" the input resulted in improved output. But this was also affected by the resolution, and it is suggested not to use skeletonize for input with very low resolution.

Bilateral Filters and Adaptive Thresholding :
These tests were started before the mid-term, and are explained in details here and here, respectively.
However, I continued checking the combinations, and they were found to be mostly useful.

I will write one last post about me, myself, life, the universe and everything that happened this summer. So Long.