iPad why number of pages in epub is 2 times of pades in pdf

Pusadee · 05-23-2012, 06:07 AM

I use pdf file = 12 pages and i save it in jpeg(12 Files).
And zip 12 jpeg file
Then use calibre to epub file
epub output file will have 25 pages

Mikou · 05-23-2012, 07:40 AM

I'm going to assume that the font size and the line spacing and character spacing are the same in both files. (If they are different, that could certainly add to the difference in page numbers.) If they are the same: the pdf page breaks are set by the creator of the pdf. Many pdf readers are not reflowable, so they will simply shrink or enlarge that page to make it fit on the screen. The page, however, will have the same number of lines and will break in the same place no matter the screen size of your device.

Epub, on the other hand, uses a set page size. I'm not sure if it's the number of lines or number of characters that is used to determine that size. It creates page breaks where needed so as not to go over that page size limit. This is most likely what is increasing your page count.

This is the way I understand it. I invite anyone to add their thoughts if what I've said is inaccurate.

FlorenceArt · 05-23-2012, 09:04 AM

I have never tried to do this, but I assume that Calibre adds a page break after each jpeg file. But if the jpeg already fills the page, the page break is on the next page. So you have:

image (page 1)
page break (page 2)
image (page 3)
page break (page 4)
etc

You should probably ask your question in the Calibre forum to get more useful answers.

Mikou · 05-25-2012, 12:58 AM

Sorry. While formulating my reply, I forgot that you said you were working with jpeg images. FlorenceArt's post sounds right.

05-23-2012, 06:07 AM	#1
Pusadee Junior Member Posts: 1 Karma: 10 Join Date: May 2012 Device: ipad2	why number of pages in epub is 2 times of pades in pdf I use pdf file = 12 pages and i save it in jpeg(12 Files). And zip 12 jpeg file Then use calibre to epub file epub output file will have 25 pages

05-23-2012, 07:40 AM	#2
Mikou Zealot Posts: 148 Karma: 5052779 Join Date: May 2007 Location: Long Island, NY Device: Kobo Libra, Amazon Fire 10, Kobo Clara, Kobo Aura One	I'm going to assume that the font size and the line spacing and character spacing are the same in both files. (If they are different, that could certainly add to the difference in page numbers.) If they are the same: the pdf page breaks are set by the creator of the pdf. Many pdf readers are not reflowable, so they will simply shrink or enlarge that page to make it fit on the screen. The page, however, will have the same number of lines and will break in the same place no matter the screen size of your device. Epub, on the other hand, uses a set page size. I'm not sure if it's the number of lines or number of characters that is used to determine that size. It creates page breaks where needed so as not to go over that page size limit. This is most likely what is increasing your page count. This is the way I understand it. I invite anyone to add their thoughts if what I've said is inaccurate. Last edited by Mikou; 05-23-2012 at 07:43 AM. Reason: Clarification & spelling correction

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05-23-2012, 09:04 AM	#3
FlorenceArt High Priestess Posts: 5,761 Karma: 5042529 Join Date: Jul 2008 Location: Montreuil sous bois, France Device: iPad Pro 9.7, iPhone 6 Plus	I have never tried to do this, but I assume that Calibre adds a page break after each jpeg file. But if the jpeg already fills the page, the page break is on the next page. So you have: image (page 1) page break (page 2) image (page 3) page break (page 4) etc You should probably ask your question in the Calibre forum to get more useful answers.

05-25-2012, 12:58 AM	#4
Mikou Zealot Posts: 148 Karma: 5052779 Join Date: May 2007 Location: Long Island, NY Device: Kobo Libra, Amazon Fire 10, Kobo Clara, Kobo Aura One	Sorry. While formulating my reply, I forgot that you said you were working with jpeg images. FlorenceArt's post sounds right.

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