Text Extraction from Image Using GAMMA Correction Method.

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 03 Issue: 01 | Jan-2016 www.irjet.net p-ISSN: 2395-0072
© 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 747
Text Extraction From Image Using GAMMA Correction Method.
1 Gholap Vidya, 2 Jadhav Pranali, 3 Lokhande Manasi, 4 Magare Niyati
1 Student, Computer Engineering, kkwieer, Maharashtra, India
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Abstract - Text extraction is the task of automatically
extracting structured information from instructed or semi-
structured machine readable documents. When one scans a
paper page into a computer produces just an image file, a
photo of the page. The computer cannot understand the
letter on the page so we need to extract text from image file.
Text extraction from image is one of the complicated areas
in digital image processing. Text data present in images
contain useful information. We can extract text and layout
information from image file. It is a complex process to detect
and recognize the text from images due to their various
sizes, gray scale and complex background. Various
researchers used the method such as morphological filters,
comic text extraction method, connect component labeling
algorithm and mathematical morphology which gives less
accuracy. In proposed system gamma method is used which
may give more accuracy as compared to the existing
methods. In gamma method it suppressed non-text
background details from the image by applying appropriate
gamma value and to remove non text region and makes the
image accurate and extract the text from image.
Key Words: Text Extraction, Text Recognition , Gamma
method, Image Processing .
1. Introduction
Images can be broadly classified into Document images,
Caption text images and Scene text images. A document
image (Figure 1a) usually contains text. Document images
are acquired by scanning journal, printed document,
degraded document images, handwritten historical
document, and book cover etc. The text may appear in a
virtually unlimited number of fonts, style, alignment, size,
shapes, colors, etc. Extraction of text in documents with
text on complex color background is difficult due to
complexity of the background and mix up of color of fore-
ground text with colors of background.
Caption text is also known as Overlay text or Cut line text.
Caption text (Figure 1b) is artificially superimposed on the
video/image at the time of editing and it usually describes
or identifies the subject of the image/video content. These
types of caption text include moving text, rotating text,
growing text, shrinking text, text of arbitrary orientation,
and text of arbitrary size.
Scene text (Figure 1c) appears within the scene which is
then captured by the recording device i.e. text which is
present in the scene when the image or video is shot.
Scene texts occur naturally as a part of the scene and
contain important semantic information. It is difficult to
detect and extract since it may appear in a virtually
unlimited number of poses, size, shapes and colors, low
resolution, complex background, non-uniform lightning or
blurring effects of varying lighting, complex movement
and transformation, unknown layout, uneven lighting,
shadowing and variation in font style, size, orientation,
alignment & complexity of background.
Due to very fast growth of available multimedia
documents and growing requirement, studies in the field
of pattern recognition shows a great amount of interest in
efficient extraction of text, indexing and retrieval from
digital video/document images. The text characters are
difficult to be detected and recognized due to their
deviation of size, font, style, orientation, alignment,
contrast, complex colored, textured background. Intensive
research projects are performed for text extraction in
images by many scholars. Several techniques have been
developed for extracting the text from an image. The
proposed methods were based on morphological
operators, wavelet transform, artificial neural network,
skeletonization operation, edge detection algorithm,
histogram technique etc .

Fig1. (a) Fig1. (b) Fig1. (c)
Document_image Caption_image Scenec_image
1.1 Literature overview
According to Siddhartha Brahma, the text extraction from
image is done by using the shape context matching [1].
According to Ruini Cao, Chew Lim Tan – the separation of
overlapping text from graphics is a challenging problem in
document image analysis. So they used a specific method
for detecting and extracting characters that are touching
graphics. It is based on the observation that the
constituent strokes of characters are usually short
segment in comparison with those of graphics. It combines
line continuation with the feature line width to decompose
and reconstruct segments and improved the percentage of
correctly detected text as well as the accuracy of character
recognition significantly [2].
Q. Yuan, C. L. Tan presented a well designed method that
makes use of edge information to extract textual blocks
from the gray scale document images. It aims at detecting
textual regions on heavy noise infected newspaper images
and separate them from graphical regions. The algorithm
traces the feature points in different entities and then
groups those edge points of textual regions. By using the
line approximation and layout categorization, it can
successfully retrieve directional placed text blocks. Finally
they used a connected component merging to gather
homogeneous textual regions together within the scope of
its bounding rectangles. They tested this method on a
large group of newspaper images with multiple page
layouts, promising results approved the effectiveness of
their Method [3].
Kohei Arai and Herman Toll stated that Reading digital
comic on mobile phone is demanding now. Instead of
creating new mobile comic contents, adaptation of the
existing digital comic web portal is valuable. In this paper,
they proposed an automatic e-comic mobile content
adaptation method for automatically creating mobile
comic content from digital comic website portal.
Automatic e-comic content adaptation is based on the
comic frame extraction method combined with additional
process to extract comic balloon and text from digital
comic page. Their proposed method is an effective and
efficient method for real time implementation of reading
e-comic comparing to other methods. From their
Experimental results they showed a 100% accuracy of flat
comic frame extraction, 91.48% accuracy of non-flat comic
frame extraction, and about 90% processing time faster
than previous method [4].
Pan et al. [5] projected a text region detector to estimate
the text existing confidence and scale information in image
pyramid, which helped to segment candidate text
components by local Binarization. A conditional random
field (CRF) model considering unary component
properties and binary contextual component relationships
with supervised parameter learning to remove non text
was proposed. Finally, text components were grouped into
text lines/words with a learning-based energy
minimization method.
Chucai et.al [6] proposed an algorithm that was able to
model both character appearance and structure to
generate representative and discriminative text
descriptors. The article Gayathri et.al
[7] discussed in detail about the various existing schemes
on extracting the text from an image
1.2 Text Extraction(Gamma Method Rules)
Rule 1: If the value of Energy > =0.05, find an instance
wherethreshold value is 0.5 from the table. If more than
one instances are found, select an instance which has
maximum value of Contrast and Energy>=0.05. If there is
no instance found, find an instance where threshold value
is next nearer to 0.5. The corresponding gamma value of
this selected instance is the estimated gamma value.
Rule 2: If the value of Energy < 0.05 and the value of
Contrast>=1000, find an instance which has the value of
Energy>=0.1, the value of Contrast>=1000 and threshold
value of 0.5 from the table for the Gamma values 1 to 10. If
more than one instance is found, select an instance which
has the value of Energy maximum and the value of
Contrast > 1000. If there is no such instance found, find an
instance in between gamma value of 0.1 and 0.9 such that

value of the threshold should be nearer or next nearer
value of 0.5. The corresponding gamma value of this
selected instance if the estimated gamma value.
Rule 3: If the value of Energy < 0.05 and the value of
Contrast<1000, find an instance which has the value of
Energy>=0.1, the value of Contrast is maximum and the
maximum contrast value should be greater than 100 for
the Gamma values 1 to 10.If no such instance found, find
an instance in between gamma value of 0.1 and 1 such that
value of the threshold should be nearer or next nearer
value of 0.5. The corresponding gamma value of this
selected instance is the estimated gamma value. Text
Extraction from Image using Gamma Correction Method
Use a zero before decimal points: “0.25,” not “.25.” Use
“cm3,” not “cc.” (bullet list)
2. Experiment Result
1. Original image
2. Open image
3. Gray Scale of image
4. Binarization of image
3. CONCLUSIONS
There are many applications of a text extraction such as
Keyword based image search, text based image indexing
and retrieval , document analysis, vehicle license detection
and recognition, page segmentation , technical paper
analysis, street signs, name plates, document coding,
object identification, text based video indexing, video
content analysis etc. The Gamma Correction approach got
the average precision rate of 78% and recall rate of 96%.
Gamma Correction method outperforms the existing
methods. So, we can retrieved text from any image,
improve the quality, accuracy & maintain the database of
image.
REFERENCES
[1]. Siddhartha Brahma , “Text Extraction Using Shape
Context Matching”. COS429: Computer Vision. Vol.1, Jan
12, 2006.
[2]. Ruini Cao, Chew Lim Tan, “Separation of overlapping
text from graphics,” vol.29,no.1, pp.20-31, Jan/Feb 2009.

[3]. Q. Yuan, C. L. Tan ,“Text Extraction from Gray Scale
Document Images Using Edge Information,” proceedings
of sixth international conference on document analysis
and recognition, pp.302-306, 2001.
[4]. Kohei Arai and Herman Tolle, “Automatic E-Comic
Content Adaptation,” International Journal of Ubiquitous
Computing (IJUC) vol.1, Issue(1), pp1-11, 2010.
[5]. Y. F. Pan, X. Hou, and C. Liu. A hybrid approach to
detect and localize texts in natural scene images.
IEEEvTrans. on Image Processing, 20(3):800–813, 2011.
[6]. Chucai Yi and Yingli Tian,”Text Extraction from Scene
Images by Character Appearance and Structure Modeling
“,Computer Vision and Image Understanding, Volume 117,
Issue 2, February 2013, Pages 182–194.

Text Extraction from Image Using GAMMA Correction Method.

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