jpeg pictures in Libreoffice 4.2.3.3 writer not very clear

joham34 · 05-08-2014, 08:40 AM

Quote:

Originally Posted by jlinkels

When you create two documents, one in old LO, one in the most recent version of LO.
In each document you past the same JPG picture. The picture should be a reasonable size, so the size is significant as compared to the overhead, 200k or so.

When you save the two documents, is there a significant difference in size of the two?

You see, the JPG image in the old version resembles an image with a compression quality of ~80. While the image in the new version seems to be compressed with quality=30.

Now LO is not supposed to compress or change the quality. But if you compare the sizes of the two version you might see a hint in a direction.

jlinkels

No, not really , both jpeg images appear same size. I have already mentioned it in a previous reply. I measured the dimensions of the jpeg image with a ruler, and is identical . As a matter of fact, my jpegs are scanned with a quality of 75 , you gessed right but with the new LO appear of low quality

jlinkels · 05-08-2014, 09:41 AM

I understood that the size of the JPGs is different. But I want to know if the size of the LO documents is different. The .odt file.

But you need to use a JPG of decent size. It must be considerably larger than the overhead of the .odt file so any size differences of the .odt file are clear.

I want to know if LO secretly does some compression.

jlinkels

joham34 · 05-08-2014, 02:50 PM

Quote:

Originally Posted by jlinkels

I understood that the size of the JPGs is different. But I want to know if the size of the LO documents is different. The .odt file.

But you need to use a JPG of decent size. It must be considerably larger than the overhead of the .odt file so any size differences of the .odt file are clear.

I want to know if LO secretly does some compression.

jlinkels

I have an 22 inch monitor.
The size of the JPGs is same.
The size of the odt file is almost the same, in the new L.O the size is slightly bigger, about 2 mm at the vertical and no clear difference of the horizontal dimension
JPEG files are much smaller than the odt dimension. In the thumbnail, I crop a side to side part of a screenshot (the whole archive is much larger than 256 kb which is the max I can upload here.

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jlinkels · 05-08-2014, 03:02 PM

The file size of the .ODT document.

jlinkels

joham34 · 05-09-2014, 12:21 AM

Quote:

Originally Posted by jlinkels

The file size of the .ODT document.

jlinkels

File size is identical eg 213,4 kb for a particular .odt document in both cases

jlinkels · 05-09-2014, 07:16 AM

Then it must be a change in the algorithm which decompresses the JPG and show it on screen. It looks like a regression error. Too bad. Have you checked the LibeOffice forums and mailing lists?

jlinkels

joham34 · 05-10-2014, 12:33 PM

Quote:

Originally Posted by jlinkels

Then it must be a change in the algorithm which decompresses the JPG and show it on screen. It looks like a regression error. Too bad. Have you checked the LibeOffice forums and mailing lists?

jlinkels

Yes, you are probably right, it looks like a regression error I already opened a thread in LO forum but no answer so far
Thank you for your help