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<noinclude>{{TOCright}}[[Category:Activities|View Slides]]</noinclude>
== Description & Goals==
== Description & Goals==
Just like Read Etexts has advantages over using PDFs with the core Read activity, View Slides has the potential to be easier to use and perform better for books composed of scanned page images than core Read is with scanned page images converted to PDFs. With PDFs of scanned page images there is often a lag before a page image becomes visible, and moving from page to page can be awkward because there is a point where you see the bottom of one page and the top of the next, rather than cleanly moving from one page to the next. Getting a full page image to appear in the screen is difficult; with View Slides it is easy and automatic.
Just like Read Etexts has advantages over using PDFs with the core Read activity, View Slides has the potential to be easier to use and perform better for books composed of scanned page images than core Read is with scanned page images converted to PDFs. With PDFs of scanned page images there is often a lag before a page image becomes visible, and moving from page to page can be awkward because there is a point where you see the bottom of one page and the top of the next, rather than cleanly moving from one page to the next. Getting a full page image to appear in the screen is difficult; with View Slides it is easy and automatic.
You can compare Read with PDF to View Slides by downloading the book "Jack and the Giants" from the Internet Archive in PDF format, then downloading the zipped image format I have created. Links to both are in the sections below.
In the future the core Read Activity will be able to read zipped image files also, but judging from my experience doing that with evince (which Read uses code from) View Slides should still give you a better experience.
The latest version of Read has excellent support for the Deja Vu format, which is also available from the Internet Archive. This format is especially designed to compress scanned book pages more than JPEG can without losing image quality. This format, like PDF, is available from the Internet Archive and may be the format to beat for scanned books.
== Creating Slide Collections ==
== Creating Slide Collections ==
* Document sharing is reliable but slow. Currently it uses Tubes to copy a file from one computer to another. When using Gabble the file is Base 64 encoded and sent using a method that has a lot of overhead, which is necessary because the two computers might be on different networks and have to deal with with firewalls and the like. You can minimize the problem by shrinking your images with "mogrify" as described above. This not only improves document sharing, it also improves performance and dramatically cuts down on disk space usage, which is vitally important on the XO!
* Document sharing is reliable but slow. Currently it uses Tubes to copy a file from one computer to another. When using Gabble the file is Base 64 encoded and sent using a method that has a lot of overhead, which is necessary because the two computers might be on different networks and have to deal with with firewalls and the like. You can minimize the problem by shrinking your images with "mogrify" as described above. This not only improves document sharing, it also improves performance and dramatically cuts down on disk space usage, which is vitally important on the XO!
* [https://github.com/sugarlabs/viewslides/issues Github Issues]
== Source ==
== Source ==
http://git.sugarlabs.org/projects/viewslides
* [https://github.com/sugarlabs/viewslides Github]
* [http://activities.sugarlabs.org/en-US/sugar/addon/4039 ASLO page]