Compression of PDF - e.g. Bible shorter than .txt

[#1]

Dear Community

I found the (german) Bible under https://info2.sermon-online.com/german/MartinLuther-1912/ 

In this the PDF-version (3'736 KB) is much shorter than the TXT-version (4'368 KB) :

	Martin_Luther_Uebersetzung_1912.pdf	2016-03-15 08:09	3.6M
	Martin_Luther_Uebersetzung_1912.txt	2014-02-03 00:06	4.2M

I counted the character (of the pure text) and found 4'016'646 charachters in the TXT-version. The PDF-version is less (3.6M only). How is it possible? 

Thanks for any explanation.

Bruno Meier

[#2]

Dear Community

I found the (german) Bible under https://info2.sermon-online.com/german/MartinLuther-1912/ 

In this the PDF-version (3'736 KB) is much shorter than the TXT-version (4'368 KB) :

	Martin_Luther_Uebersetzung_1912.pdf	2016-03-15 08:09	3.6M
	Martin_Luther_Uebersetzung_1912.txt	2014-02-03 00:06	4.2M

I counted the character (of the pure text) and found 4'016'646 charachters in the TXT-version. The PDF-version is less (3.6M only). How is it possible? 

Thanks for any explanation.

Bruno Meier

[#3]

This is the result of text compression.

[#4]

Of course!

But how ist it done?

Does PDF not need 8 Bit per character?

[#5]

A PDF uses more space than TXT but then it is compressed. To oversimplify, parts of the file as ZIP compressed. ZIP your text file, it will probably be smaller still. 

[#6]

Read this:

https://www.prepressure.com/library/compression-algorithm/flate-deflate

A simple example:

When there are 5 characters "a" the algorithm uses onle one "a".

[#7]

Thanks. ZIP-compression is much stronger. The TXT-version (4'368 KB) of the Bible by ZIP use 32.5% only.

[#8]

Thanks for the hint in the "flate-deflate". By the way: there are some 2% of multible characters in Bible text.

kind regards

Bruno Meier

[#9]

I posted a simplified example.

[#10]

Yes