Author Topic: Images do not insert, or sometimes they do but disappear  (Read 7840 times)

turfhugger

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Images do not insert, or sometimes they do but disappear
« on: April 20, 2011, 06:54:55 am »
The title says it all, but here's a little more...
I'm using Version 1.4.0.rc3 on a macbook.
I insert a frame, then "Get Image" and sometimes an image shows up, about 50% of the time. Then I scroll down and work on my next page, then scroll up and...??? WTF. Just gone! :-\

UPDATE: I'm new to Scribus so I'm still wrapping my head around it I found this, which helped me solve my problem:
Scribus does not actually embed the image file into the Scribus document; this is another DTP standby — by keeping the files separate, artists can make updates to the images without the page designer having to re-import everything. Source: http://blog.worldlabel.com/2009/free-desktop-publishing-with-scribus-open-source.html

Okay, so it doesn't act like a paste function, it's more like a link and when you change the location of the image, the link is broken...right? Well it makes sense to me.

So why is it that jpegs are not showing 50% of the time? My theory is that I had too many files on my desktop and due to limited memory on my desktop, it caused for this link to be broken... but I've fiddled around and it doesn't matter where I host the images on my computer, they don't want to show up, very frustrating.

PLEASE HELP!
« Last Edit: April 20, 2011, 10:15:39 am by turfhugger »

RussellCollier

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Re: Images do not insert, or sometimes they do but disappear
« Reply #1 on: August 24, 2012, 06:23:26 pm »
Did anybody ever get back to you on this topic? Or did you solve it somehow? I am experiencing the same problems.

a.l.e

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Re: Images do not insert, or sometimes they do but disappear
« Reply #2 on: August 25, 2012, 08:28:35 am »
we had recently a user who could track down the problem to having a directory being an alias (a symlink) to another directory...
does it apply to you, too?

the other way to have images disappearing is to rename them or to move them to another directory: in scribus images are only linked and not inserted in the scribus file! so it matters where they are on the disk!

RussellCollier

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Re: Images do not insert, or sometimes they do but disappear
« Reply #3 on: August 25, 2012, 09:09:34 am »
Thanks. My problem appears to be connected to the size of the image I am trying to import. Files of the 1 to 2 Mb range seem okay. Files 6 Mb or larger seem to choke the Scribus, and force a non-display.

It is not due to the movement of files, as I have been very careful to maintain exact links.

When I reduce the size of the import files, quite suddenly they appear on-screen, and are no longer missing. Tha is so far the single variable I can find that makes any difference.

Thank you for your thoughts.

Best,
Russell

a.l.e

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Re: Images do not insert, or sometimes they do but disappear
« Reply #4 on: August 26, 2012, 01:11:43 am »
... in this case i tend to believe that you don't have enough RAM to manage the images with scribus (and, yes, scribus is not as good at managing bitmaps as gimp is...)

but., who knows?, maybe there is indeed a problem with scribus...

ciao
a.l.e

RussellCollier

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Re: Images do not insert, or sometimes they do but disappear
« Reply #5 on: August 26, 2012, 04:31:14 am »
... in this case i tend to believe that you don't have enough RAM to manage the images with scribus (and, yes, scribus is not as good at managing bitmaps as gimp is...)

but., who knows?, maybe there is indeed a problem with scribus...

ciao
a.l.e

Hm. Interesting. 16 GB is not enough RAM? Is there a way to tell how much RAM Scribus is using? And is there a way to tweak how much RAM it gets?

I think I might replace all my hi-rez PNGs (6 MB to 21 MB) with medium-rez (1-3 MB). I could see that the PNGs actually expand out a lot in memory. The 21 MB PNG, for example, used up 336.1 MB of memory. Dropping the resolution, filesize, etc., could make a real difference.

A confusion on my part is understanding the difference between DPI and PPI. I have no way of knowing if a file I resized to 150 DPI, which reads as something close to 150 PPI at actual DPI is any good for printing. I am used to having specs for printout-ready PDFs to be set to minimum 300 DPI. My client's printer will almost certainly want 300 DPI or better. I have been told 1200 DPI for some of the maps and photos would be better than 300 DPI.

What relation this has to PPI still puzzles me. Yes, I have read and re-read the explanations, and they are written for specialists who already know all about this stuff. I'm not a tech newbie - I've been in the mapping world for 20 years for example - and the explanations still do not really help me make sense of it all. I've no easy rule to follow, and presenting me with a set of formulae to calculate doesn't help me make sense of what choices to make in Scribus when I import hi-rez pics and maps into a project.

Anyway. So 16 Gigs is still not enough for Scribus. This is a Mac Pro I just bought. High-end for laptops. Also not upgradeable. If 16 Gigabytes is not enough for Scribus, how much does it really need? Where would I find such a power monster? Alternatively, if Scribus cannot function without more than 16 GB, why would I bother learning how to use it if it is too power hungry for most available hardware?

Anyway. Perhaps I am still missing something here.

Best,
Russell

Nermander

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Re: Images do not insert, or sometimes they do but disappear
« Reply #6 on: August 26, 2012, 09:24:17 pm »
Most of the time, when people talk about DPI the really mean PPI.

PPI is pixels per inch.

An image of 300x300 pixels printed as 2x2 inches will be printed at 150 PPI.

DPI (dots per inch) usually means "raster dots". How manu raster dots that are used for a pixel depends in the printing method. For example a lot of inkjet printers are advertised as 1440 DPI. That does NOT mean they will print 1440 pixels on an in, usually they print only 240 PPI but using 6x6 raster dots for each pixel.

Try googling for "DPI vs PPI" and you will find dozens of pages explaining this.

For printing we also have LPI...

RussellCollier

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Re: Images do not insert, or sometimes they do but disappear
« Reply #7 on: August 26, 2012, 11:19:01 pm »
Thanks, that helps. So, I am finding that GIMP will let me scale an image down to approximately the size I need (e.g., 6 inches by 4 inches), and also scale the resolution to what I need (e.g., 300 PPI, or 150 PPI). Perhaps if I get this thing figured out for production processing, I will write up a short "how-to" as contribution to the Scribus community.

I still have a question about the usefulness of my laptop versus Scribus's capabilities. It has been suggested on this forum that perhaps I simply lack the RAM to properly display hi-resolution images. I have a very new Macbook Pro (Retina) with 16 GB RAM. Is this too small to display images properly in Scribus?

Or perhaps I have simply not set something correctly - is there a setting somewhere I can tweak to use more of my RAM for Scribus?

Or perhaps it is simply the image set itself. Perhaps I have set the PPI/DPI/Real Size at too large for Scribus?

And finally, what kinds of image size limits does Scribus have? Where do I find out its limitations? I know Scribus is supposed to me a memory hog, but perhaps there is a way to learn what those memory limitations are and learn how to work within them? Where would I look for such a topic? If it is very technical, how would I reduce jargon to simple instructions (e.g., First, tweak these settings, second tweak your images, third check it all here).

Okay, I am appreciating that you fellows have made time to discuss this with me. I think Scribus has come a very long way since I first tried it out years ago. Scribus is becoming increasingly sophisticated, and in my opinion, increasingly useful. I still have some questions.

Best regards,
Russell in Canada.

GarryP

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Re: Images do not insert, or sometimes they do but disappear
« Reply #8 on: August 27, 2012, 10:30:28 pm »
Russell, you can check the memory status of your MacBook Pro (or any other Mac running OS X) by using the Activity Monitor utility (it's a bit like the Task Manager in Windows).

First open the Applications folder (the normal shared system one, not the one in your user account). Then open the Utilities folder in that folder. Then open the Activity Monitor utility (it looks like a heart monitor).

The tabbed area at the bottom of the window should have a System Memory tab, just click on it.

The "memory pie" graphic will be split up into four sections:
Green - free memory that's not being used by anything,
Blue - memory that the OS is holding onto for now in case it needs it (but might be freed later),
Yellow - memory being used by applications currently running,
Red - it's complicated, but just think of it as unusable by applications.

If your "memory pie" has more than a quarter of it showing as green then you're fine memory-usage-wise. If the green slice is tiny (or invisible) then you might have a problem (especially with 16GB installed).

The list of applications above the tabbed area shows what memory is being used by each application but the explanation of each type is way beyond what this forum is about.

I hope this helps.

RussellCollier

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Re: Images do not insert, or sometimes they do but disappear
« Reply #9 on: August 28, 2012, 02:31:10 am »
Wow, that is actually really useful. Many thanks. I see that with Scribus loaded, I am using 2.45 Gb memory. I have something like 60% to 65% System Memory still free after all processes are taken into account.

My brand new laptop is in fact nicely suited to Scribus. Yes, that looks something like the way Windows presents information about memory, doesn't it?

Being able to conclude that Scribus works well with modest images (number or size), I can guess that with very high resolution pics, the memory usage of Scribus will climb rapidly to meet the demand. Still do not know if there is in fact any kind of practical ceiling with regard to file size. I only know that PNGs in the range of 10 MB to 21 MB suddenly hit some kind of barrier and Scribus can no longer find the files, even though the link is obviously still intact. Reducing some of the files' resolution and thus size makes it possible to suddenly display previously "disappeared" images.

Interesting that the 21 MB PNG swelled in size to 336 MB in memory, so a lot of pics in that 10-20 MB range might chop the memory down quickly.

Okay, I learned something new out of all this. Many thanks. Didn't get all my questions answered, but I do appreciate all your help.

Best regards,
Russell

GarryP

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Re: Images do not insert, or sometimes they do but disappear
« Reply #10 on: August 28, 2012, 03:44:56 pm »
You're welcome, I'm glad I was able to be of some assistance.

I had a few extra (not particularly related) thoughts which may be of some use to you or someone else (maybe in the future):

Firstly, images in Scribus can be displayed at a lower resolution during editing by using the "Preview Settings…" option on the context-sensitive menu. I'm not sure exactly what this does memory/performance-wise but it may be worth knowing about or tinkering with.

Secondly, I've personally found that JPEGs are generally way smaller than their equivalent PNGs, even when using lossless compression (for whatever reason). Maybe you could do some simple tests to see if changing file type makes a difference to your current issue rather than changing the resolution.

Thirdly, have you checked whether your PNGs have an alpha channel? And if so do they need one? I only ask as an alpha channel can add 20% or more to a file's size and if it's not needed you could remove it to save some space. (You can easily check this with OSX - Right click image file, select "Get Info", in the "More Info" tab it'll say whether the file has an alpha channel or not. You can remove it with GIMP, but retain the original file just in case.)

Lastly, and this really isn't relevant to this topic, and may not be an issue with Scribus at all (depending on how it has been built), and I only mention it because you're using such high resolution images, but the benefits of the Retina display aren't automatically available to all applications. Applications need to be written in a specific way, quote: "by supplying @2x image assets similar to the situation under iOS" (whatever that means!). Maybe you could start a new forum topic on this point if it's something you'd be bothered about.

Cheers, Garry.

 

palmate