Image compression using hybrid lossy and lossless technique

Other Title(s)

ضغط الصور باستخدام تقنية تعتمد على طرق منقوصة و غير منقوصة

Dissertant

al-Junaydi, Majd Yusuf Mari

Thesis advisor

Utair, Muhammad

Comitee Members

Kanan, Tariq
Nassar, Muhammad

University

Amman Arab University

Faculty

Collage of Computer Sciences and Informatics

Department

Department of Computer Science

University Country

Jordan

Degree

Master

Degree Date

2017

English Abstract

The ability to store digital data has become much easier as a result of the huge development in the capacity of the memory devices, and it has also become extremely necessary to be able to obtain store digital images over the internet.

Efficient image compression is one of the most important techniques that used to solve problems related to digital images such as the size of digital images that occupying large space on the memory.

Therefore, the transmission bandwidth and time will be a serious trouble if the compression is not implemented.

In general, image compression mainly aims to reduce the amount of data required for representing digital images which can lead to solving almost all of the problems.

Image compression technique can be classified into two types are: “lossy” and “lossless”, lossy technique, can give much greater compression ratio than the lossless compression, but misses some of content information that related to the image.

In contrast, lossless technique can give less compression ratio but it keeps the image quality.

The main idea of this thesis is to produce two hybrid (HLL1 and HLL2) compression techniques that based on lossy and lossless techniques; the first HLL technique can be implemented in two phase, the first phase is RIFD (Otair and Shehadeh, 2016) and the second phase is LM-DH (Alkhalayleh and Otair, 2014).

The RIFD technique which depends on increasing the redundancy and similarity among the neighboring pixels of images by rounding the pixel’s intensities followed by the dividing process, which makes compression possible.

The second phase is to apply LM-DH that belongs to lossless technique which was used to solve problems existed in the Huffman standard.

Huffman standard meet a large size of the length code problem for every color intensity, therefore can be effect on the compression ratio and the size of compressed image.

LM-DH technique reduces tree depth by decomposing the Huffman tree that into 4 sub-trees, also in order to enhance the compression ratio.

The second HLL is to apply RIFD with LZW, that can be done in two phase, the first phase RIFD that mentioned previously, the second phase is apply LZW that related to lossless technique, which is implemented through construct a dictionary includes all the color intensity values, these values can be saved as a string and find the matches between the current input and the color intensity values that saved in the dictionary if it founded and matched it will be removed.

The experiments result proves the effectiveness the HLL2through provide up to 0.61 of improvement compression ratio and get 0.74 as average with keeping the images quality after decompression stage

Main Subjects

Information Technology and Computer Science

Topics

• Information retrieval
• Image compression

No. of Pages

138

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-764292