MPEG-4 Part 14 (which is one part of the Moving Picture Experts Group’s MPEG-4 suite of standards for compressing streams of audio and video) is a file format type also referred to as MPEG-4, mp4, and m4a (among others), used to store digital audio and digital video streams. The official filename extension MPEG-4 Part 14 files is .mp4. (According to the Wikipedia article: MPEG-4 Part 14).
The Library of Congress' site on digital preservation of file formats states, "This format is intended to serve web and other online applications; mobile devices, i.e., cell phones and PDAs; and broadcasting and other professional applications."
According to a page found on NYU’s film preservation site, the fact that MPEG-4 files are able to contain audio, video, and subtitle streams makes it difficult to determine the content of these files, and could cause problems when migrating the files, as the different types are all encoded differently. Apple began using the .m4a file extension to distinguish certain audio files from other types of MP4s, but it is not universally held and some audio MP4s will not have this file extension. The format also includes a standardized intellectual property protection coding which could make it difficult to playback those files in the future.
While the audio MP4 files are considered to be of superior quality with smaller file sizes than MP3s, some say that licensing reasons keep MP4s from becoming more popular. The NYU site states, “The MP4 file is open standard; however, the codecs (compression schemes) are commercially licensed. Over two dozen companies claim patents on the MPEG4 suite. These licenses cover the manufacture and sale of devices or software and, for some content disseminators, levy fees according to number of endusers or the extent of content delivered.” The fact that mp4s are not as widely popular, may mean that they will become obsolete in the future. The NYU site further states that, “The Florida Center for Library Automation (FCLA) digital archive has given the file format a rating of "low-confidence" for its digital preservation recommendations.”
MPEG-4 files can be played by: iTunes, QuickTime Player, Winamp, RealPlayer, VLC Media Player, foobar2000, Avidemuxiola, KSP Sound Player, Media Player Classic, MPlayer, and Nero Media Player.
Apple includes an info page on MPEG-4s; they write that their QuickTime application was the foundation for development of the mulitmedia MP4 files. http://www.apple.com/quicktime/technologies/mpeg4/. They write, "Just as QuickTime does, MPEG-4 also scales to transport media at any data rate — from media suitable for delivery over dial-up modems to high-bandwidth networks." And it seems like this is one of the main importances of this format- it's ability to provide higher quality files over a variety of different data rates. They also write on the Apple site that the MPEG-4 standard allows interoperability between different playback products.
Thursday, September 25, 2008
Thursday, September 18, 2008
Image Management/Editing Software
Today I’m researching and writing about image management software (IMS) and image editing software (not to be confused with Digital Asset Management Systems!). I’ll sketch out a general definition of these kinds of tools, however, since we are talking about different, unique software programs that do very different things, there is often crossover in terms of functionality. It just really depends on what the software you decide to get can actually do, and what you need for your particular digitization project.
My professor Maria Esteva gives a good general description of these image management/editing programs in a report that she wrote in 2007 for the Texas Heritage Digitization Initiative called, “Recommendations and Best Practices for Management of Derivative Digital Objects,”
“The purpose of IMS is to aid imaging projects from image creation in a scanner or digital camera, through storage in a hierarchical file storage system, digital assets management system (DAM), or institutional repository system (IR). Available in the market and as open source free tools there are various types of IMS with different functionalities. “
Image management software and image editing software help between the stages of capturing the image and getting the image to its somewhat final resting place, when it is published or somehow made available to users. Esteva further states that image management/editing software can be used to enhance and edit images (crop, color correct, resize, rename, etc.), while other products edit and help to organize and describe images, which can be very helpful if you are dealing with a great number of images.
While depending on your project you may decide that you need to purchase a product, there are also freeware versions of image management software items that can be used if you are operating on a shoestring, as many preservation projects are. Some of these are open-source, which means that they can be played with and manipulated to suit the purposes of your program. It is important to have someone on your team with some programming background if this is the option that you choose.
TASI (a non-profit digital media resource center from the UK) did a survey of different types of image management software and compares them here: http://www.tasi.ac.uk/advice/delivering/imsoftware.html
It was updated in Februrary, 2008, so it should be pretty up-to-date, though these things are always changing.
Just a few (of many) things to keep in mind when looking for the image management software for your projects are:
• What file formats does the software support? Just a few, or tons? You may just need a few, but it helps to have different formats if you want to have master files, and derivatives.
• Are you able to rename, resize, convert formats, easily copy/move/delete images from various locations, create categories of images, view thumbnails or other versions of the images, and edit/crop? Can you do these things in batches? That’s important because batch processing can save lots of time, which saves money.
Also, in terms of image editing, TASI writes, “Some systems will apply edits directly to the image as you make them - which makes it impossible to recover an earlier version if you change your mind. Some systems will create a copy, providing you with a level of version control. Other systems store details of the edits you make and only actually apply them to the image when it is exported or saved into a different size or format” (http://www.tasi.ac.uk/advice/delivering/choose-ims.html).
• Can you easily navigate and search within the images?
• Can you use descriptive metadata to search, retrieve and track the project status (in batches)? Can this descriptive metadata and other technical metadata be moved to other systems easily?
• Does it automatically create backup copies?
• Is it easy to record who did what to which images? Can you control who is able to do what? Since IMS can be used to manage workflows this can be important. The TASI site states, “If you're using a system to manage your workflow, then versioning and auditing features (e.g. who edited the image) are worth looking out for. These can support your quality assurance (QA) processes, helping you to pick out where any errors may be being introduced” (http://www.tasi.ac.uk/advice/delivering/choose-ims.html).
The TASI site points out that with commercial products it is important to keep in mind that the vendors may not stay in business in order to be able to update the systems or provide service on them. You also may not be able to change or even know about certain parts of a commercial software package. And finally, many of these software products are not made for educational or heritage markets, but instead for professional photographers and corporate clients (http://www.tasi.ac.uk/advice/delivering/ims2.html).
My professor Maria Esteva gives a good general description of these image management/editing programs in a report that she wrote in 2007 for the Texas Heritage Digitization Initiative called, “Recommendations and Best Practices for Management of Derivative Digital Objects,”
“The purpose of IMS is to aid imaging projects from image creation in a scanner or digital camera, through storage in a hierarchical file storage system, digital assets management system (DAM), or institutional repository system (IR). Available in the market and as open source free tools there are various types of IMS with different functionalities. “
Image management software and image editing software help between the stages of capturing the image and getting the image to its somewhat final resting place, when it is published or somehow made available to users. Esteva further states that image management/editing software can be used to enhance and edit images (crop, color correct, resize, rename, etc.), while other products edit and help to organize and describe images, which can be very helpful if you are dealing with a great number of images.
While depending on your project you may decide that you need to purchase a product, there are also freeware versions of image management software items that can be used if you are operating on a shoestring, as many preservation projects are. Some of these are open-source, which means that they can be played with and manipulated to suit the purposes of your program. It is important to have someone on your team with some programming background if this is the option that you choose.
TASI (a non-profit digital media resource center from the UK) did a survey of different types of image management software and compares them here: http://www.tasi.ac.uk/advice/delivering/imsoftware.html
It was updated in Februrary, 2008, so it should be pretty up-to-date, though these things are always changing.
Just a few (of many) things to keep in mind when looking for the image management software for your projects are:
• What file formats does the software support? Just a few, or tons? You may just need a few, but it helps to have different formats if you want to have master files, and derivatives.
• Are you able to rename, resize, convert formats, easily copy/move/delete images from various locations, create categories of images, view thumbnails or other versions of the images, and edit/crop? Can you do these things in batches? That’s important because batch processing can save lots of time, which saves money.
Also, in terms of image editing, TASI writes, “Some systems will apply edits directly to the image as you make them - which makes it impossible to recover an earlier version if you change your mind. Some systems will create a copy, providing you with a level of version control. Other systems store details of the edits you make and only actually apply them to the image when it is exported or saved into a different size or format” (http://www.tasi.ac.uk/advice/delivering/choose-ims.html).
• Can you easily navigate and search within the images?
• Can you use descriptive metadata to search, retrieve and track the project status (in batches)? Can this descriptive metadata and other technical metadata be moved to other systems easily?
• Does it automatically create backup copies?
• Is it easy to record who did what to which images? Can you control who is able to do what? Since IMS can be used to manage workflows this can be important. The TASI site states, “If you're using a system to manage your workflow, then versioning and auditing features (e.g. who edited the image) are worth looking out for. These can support your quality assurance (QA) processes, helping you to pick out where any errors may be being introduced” (http://www.tasi.ac.uk/advice/delivering/choose-ims.html).
The TASI site points out that with commercial products it is important to keep in mind that the vendors may not stay in business in order to be able to update the systems or provide service on them. You also may not be able to change or even know about certain parts of a commercial software package. And finally, many of these software products are not made for educational or heritage markets, but instead for professional photographers and corporate clients (http://www.tasi.ac.uk/advice/delivering/ims2.html).
Thursday, September 11, 2008
Reaction to the North Carolina ECHO Project Management Guidelines
I just finished going over the North Carolina ECHO Project Management Guidelines, which include a good, brief overview of the steps needed to manage any small or large, institutional digitization project.
One of the main points brought up is that ‘change’ is a necessary and inherent part of any of these projects, and building in the ability to not only deal with change, but to possibly use it as a tool or an asset, is an important part of succeeding at achieving your project goals. To that end, they talk about staffing your project, and the fact that while the skill sets of employees are important, a certain amount of learning and training has to happen with every position, not only once, but continually, so it is important that employees are flexible and can take direction and/or learn well. I think that this has a lot to do with the ability of everyone working on the digitization project to be able to work well with others and communicate well.
The project guidelines state that the creation of a training manual can be helpful as well, and I’ve found this to be really true. Any job that I’ve worked with that has given me a training manual (not one that is overly complicated, out-dated, or too hard to get through) has helped me to get my job done more efficiently and accurately, without having to take another person's time to answer simple questions. Of course, it is important to have people talking to people directly, to be able to answer more complex questions or take staff members through the steps initially, but too often, without a manual, employees find themselves thrown into unanticipated situations, not sure what the protocol is, and possibly doing the wrong thing until they are able to realize it through their own experience and mistakes. While learning though mistakes and experience is important, it can also sometimes be avoided with just a little bit more information at someone's fingertips. Starting new jobs can be overwhelming, and it helps to have a document that staff can refer to when they are working on their own.
I also found the break down of about how much time each part of the process should take, interesting. The actual image capture aspect was about only 15% of the process, while the rest of the tasks, like selection, preparation, creating the metadata and the Web site, and even outsourcing, took just as much time as this or more, each, (of course this is all going to depend on the project.) I think that once you have the system set up and you are digitizing massive amounts of pages or objects, more and more of the time would be spent with the actual image capture and editing, but I'm not sure, as this isn't my area of expertise.
One of the main points brought up is that ‘change’ is a necessary and inherent part of any of these projects, and building in the ability to not only deal with change, but to possibly use it as a tool or an asset, is an important part of succeeding at achieving your project goals. To that end, they talk about staffing your project, and the fact that while the skill sets of employees are important, a certain amount of learning and training has to happen with every position, not only once, but continually, so it is important that employees are flexible and can take direction and/or learn well. I think that this has a lot to do with the ability of everyone working on the digitization project to be able to work well with others and communicate well.
The project guidelines state that the creation of a training manual can be helpful as well, and I’ve found this to be really true. Any job that I’ve worked with that has given me a training manual (not one that is overly complicated, out-dated, or too hard to get through) has helped me to get my job done more efficiently and accurately, without having to take another person's time to answer simple questions. Of course, it is important to have people talking to people directly, to be able to answer more complex questions or take staff members through the steps initially, but too often, without a manual, employees find themselves thrown into unanticipated situations, not sure what the protocol is, and possibly doing the wrong thing until they are able to realize it through their own experience and mistakes. While learning though mistakes and experience is important, it can also sometimes be avoided with just a little bit more information at someone's fingertips. Starting new jobs can be overwhelming, and it helps to have a document that staff can refer to when they are working on their own.
I also found the break down of about how much time each part of the process should take, interesting. The actual image capture aspect was about only 15% of the process, while the rest of the tasks, like selection, preparation, creating the metadata and the Web site, and even outsourcing, took just as much time as this or more, each, (of course this is all going to depend on the project.) I think that once you have the system set up and you are digitizing massive amounts of pages or objects, more and more of the time would be spent with the actual image capture and editing, but I'm not sure, as this isn't my area of expertise.
Thursday, September 4, 2008
Cornell’s “Moving Theory into Practice” Tutorial
This tutorial (http://www.library.cornell.edu/preservation/tutorial/) was a great introduction to digital imaging basics, though a bit overwhelming for a beginner like me. I couldn’t process it all, but will definitely go back to it once I actually start working on projects and need the details to help me figure out what I’m doing. The additional readings looked helpful as well.
The formulas for benchmarking the quality of the digitized images, which this tutorial really stresses, were particularly difficult for me to wrap my mind around right now. I understood the underlying concepts, but found myself skimming over the details of the actual measurements. What often seems to be important is establishing reference points, so that the image outputs can be standardized, and you don’t find yourself (or the technician) making subjective judgements throughout the process. It seems that the more images that one digitizes, the harder it would be to keep the changes accurate without having these reference points to go back to. As we discussed in class, color can be particularly difficult to tweak, and can be quite subjective.
For me, the most interesting and complicated issues are those dealing with metadata and file management. These areas of digitization processes (including the networks, IT infrastructures, etc.) seem much more obscure to me than other aspects of the process (i.e. selections, scanning, and reformatting decisions) and I want to learn more about how and where the information is stored and accessed once it has been digitized. Obviously, digital preservation is also very related to these file management issues, and is something that people in our field are particularly concerned with. There don’t seem to be many answers about how to preserve all of these digital objects.
One of our readings referred to a digital project created by the BBC in the 1980s, the Domesday Project, which was related to the original Domesday Book compiled in 1086. The information collected in the 1980s (videos and more about British citizens) was almost inaccessible within just a decade and a half, as the equipment that was used to access it became obsolete. The original Domesday Book from 1086 is still readable. Here’s an article from the BBC about the project and attempts to save the info: http://news.bbc.co.uk/1/hi/technology/2534391.stm .
They finally figured it out using an emulator, but it seems like it was a huge project. Scary.
The formulas for benchmarking the quality of the digitized images, which this tutorial really stresses, were particularly difficult for me to wrap my mind around right now. I understood the underlying concepts, but found myself skimming over the details of the actual measurements. What often seems to be important is establishing reference points, so that the image outputs can be standardized, and you don’t find yourself (or the technician) making subjective judgements throughout the process. It seems that the more images that one digitizes, the harder it would be to keep the changes accurate without having these reference points to go back to. As we discussed in class, color can be particularly difficult to tweak, and can be quite subjective.
For me, the most interesting and complicated issues are those dealing with metadata and file management. These areas of digitization processes (including the networks, IT infrastructures, etc.) seem much more obscure to me than other aspects of the process (i.e. selections, scanning, and reformatting decisions) and I want to learn more about how and where the information is stored and accessed once it has been digitized. Obviously, digital preservation is also very related to these file management issues, and is something that people in our field are particularly concerned with. There don’t seem to be many answers about how to preserve all of these digital objects.
One of our readings referred to a digital project created by the BBC in the 1980s, the Domesday Project, which was related to the original Domesday Book compiled in 1086. The information collected in the 1980s (videos and more about British citizens) was almost inaccessible within just a decade and a half, as the equipment that was used to access it became obsolete. The original Domesday Book from 1086 is still readable. Here’s an article from the BBC about the project and attempts to save the info: http://news.bbc.co.uk/1/hi/technology/2534391.stm .
They finally figured it out using an emulator, but it seems like it was a huge project. Scary.
The Collodion Process
Collodion is a chemical, discovered in 1846, (see the Wikipedia entry on collodion: http://en.wikipedia.org/wiki/Collodion), and used in one of the first photographic processes, aptly named the collodion process, also known as the wet-plate process because it involves pouring of liquids onto a glass plate (Schimmelman, The Tintype in America 1856-1880, p. 13). Frederick Scott Archer first published information about this collodion process he was working on in 1851, which was notable because it created a glass plate negative rather than a positive (Schimmelman, 13). The Daguerreotype, which was popular at the time, created a single positive image. The negative created in the wet-plate collodion process could be used to create positive prints (which are called Ambrotypes [on glass with a black backing] and Tintypes [on dark metal]). Positives could also be printed on paper, such as albumen paper. These negative glass plates were also notable because the prints they created were of high quality (Schimmelman, 13-14).
According to Robert Leggat, on his Web site, which includes an interesting discussion of the history of the collodion wet-plate process, the process was faster and cheaper than other early photographic processes, which led to its popularity in the United States. Though, apparently it was also messy and not very easy to do because initially the whole process, including developing, had to happen in about ten minutes. And it was explosive. Oh, and also, because Archer didn't ever patent his process, many people were able to just do it for free, which added to its popularity (Robert Leggat, “The Collodion Process in A History of Photography, http://www.rleggat.com/photohistory/history/collodio.htm).
It was most popular from the 1850s until the 1880s, according to the Getty Museum’s Web site, which also has a video that gives a nice sort of re-enactment of the wet- plate collodion process: (http://www.getty.edu/art/gettyguide/videoDetails?cat=2&segid=1726).
The Wikipedia article on collodion lists the steps to the wet-plate collodion process
(http://en.wikipedia.org/wiki/Collodion):
* Clean the glass plate (extremely well)
* Flow the glass plate with "salted" (iodide/bromide) Collodion
* Immerse the plate in a silver nitrate bath (for 3-5 minutes)
* Expose the plate (can range from less than a second to several minutes)
* Develop the plate (using an iron based developer)
* Fix the plate (with potassium cyanide or sodium thiosulfate)
* Varnish the plate (with a varnish made from gum sandarac, alcohol and lavender oil).
In terms of the unique aesthetics of the collodion process, Schimmelman writes that the paper prints (photographs) made by the process had “the familiar look of a monochromatic wash drawing on paper, an advantage for those who by their creative energy wanted to nudge photography toward fine art” (14).
A dry-plate collodion process was created a few decades later, in 1871 by Richard Leach Maddox, according to an article, “The Preservation of Glass Plate Negatives,” by Greta Bahneman (http://www.webjunction.org/470/articles/content/439665.) This process was chemically a little bit different and basically allowed the photographer to develop the negative glass plate later, which gave them more flexibility. Bahneman gives a very detailed analysis of preservation concerns when handling the glass plates (wet and dry), and even includes a section on digitizing, suggesting that it needs to be done for preservation and access purposes, and can be completed with either a flat-bed scanner or a digital camera.
In terms of preservation and digitization, obviously the fact that the negatives are glass poses some problems.
Here is a discussion on photo.net, in which someone is asking for advice about scanning glass plate negatives: http://photo.net/digital-darkroom-forum/00QH6E . There doesn’t seem to be a real consensus about best practices for these. People on this discussion board don’t think that making prints of the negatives first, and then digitizing the prints is very necessary, or cost-effective for an organization without much money. Some said that the negatives could be digitized on scanners, but they have to be handled very carefully.
The glass can also cause reflections during the image-capture. This page from the Bancroft Library (http://bancroft.berkeley.edu/collections/casedphotos/digitization.html) describes a digitization project involving ambrotypes, and the problems faced because of the reflective surface of the glass. They were using a digital camera for this project.
According to this page, “Preservation issues in digitizing historical photographs,” created by the European Commission on Preservation and Access, which lists SEPIA (Safeguarding European Photographic Images for Access) Guidelines for preservation when digitizing old photographs, ambrotypes and tintypes are quite sensitive to abrasion as they do not have the protective covering that daguerreotypes have (http://www.knaw.nl/ecpa/sepia/workinggroups/wp4/guidelines.html).
Print source:
Schimmelman, Janice G. The Tintype in America 1856-1880. Philadelphia: American Philosophical Society, 2007.
According to Robert Leggat, on his Web site, which includes an interesting discussion of the history of the collodion wet-plate process, the process was faster and cheaper than other early photographic processes, which led to its popularity in the United States. Though, apparently it was also messy and not very easy to do because initially the whole process, including developing, had to happen in about ten minutes. And it was explosive. Oh, and also, because Archer didn't ever patent his process, many people were able to just do it for free, which added to its popularity (Robert Leggat, “The Collodion Process in A History of Photography, http://www.rleggat.com/photohistory/history/collodio.htm).
It was most popular from the 1850s until the 1880s, according to the Getty Museum’s Web site, which also has a video that gives a nice sort of re-enactment of the wet- plate collodion process: (http://www.getty.edu/art/gettyguide/videoDetails?cat=2&segid=1726).
The Wikipedia article on collodion lists the steps to the wet-plate collodion process
(http://en.wikipedia.org/wiki/Collodion):
* Clean the glass plate (extremely well)
* Flow the glass plate with "salted" (iodide/bromide) Collodion
* Immerse the plate in a silver nitrate bath (for 3-5 minutes)
* Expose the plate (can range from less than a second to several minutes)
* Develop the plate (using an iron based developer)
* Fix the plate (with potassium cyanide or sodium thiosulfate)
* Varnish the plate (with a varnish made from gum sandarac, alcohol and lavender oil).
In terms of the unique aesthetics of the collodion process, Schimmelman writes that the paper prints (photographs) made by the process had “the familiar look of a monochromatic wash drawing on paper, an advantage for those who by their creative energy wanted to nudge photography toward fine art” (14).
A dry-plate collodion process was created a few decades later, in 1871 by Richard Leach Maddox, according to an article, “The Preservation of Glass Plate Negatives,” by Greta Bahneman (http://www.webjunction.org/470/articles/content/439665.) This process was chemically a little bit different and basically allowed the photographer to develop the negative glass plate later, which gave them more flexibility. Bahneman gives a very detailed analysis of preservation concerns when handling the glass plates (wet and dry), and even includes a section on digitizing, suggesting that it needs to be done for preservation and access purposes, and can be completed with either a flat-bed scanner or a digital camera.
In terms of preservation and digitization, obviously the fact that the negatives are glass poses some problems.
Here is a discussion on photo.net, in which someone is asking for advice about scanning glass plate negatives: http://photo.net/digital-darkroom-forum/00QH6E . There doesn’t seem to be a real consensus about best practices for these. People on this discussion board don’t think that making prints of the negatives first, and then digitizing the prints is very necessary, or cost-effective for an organization without much money. Some said that the negatives could be digitized on scanners, but they have to be handled very carefully.
The glass can also cause reflections during the image-capture. This page from the Bancroft Library (http://bancroft.berkeley.edu/collections/casedphotos/digitization.html) describes a digitization project involving ambrotypes, and the problems faced because of the reflective surface of the glass. They were using a digital camera for this project.
According to this page, “Preservation issues in digitizing historical photographs,” created by the European Commission on Preservation and Access, which lists SEPIA (Safeguarding European Photographic Images for Access) Guidelines for preservation when digitizing old photographs, ambrotypes and tintypes are quite sensitive to abrasion as they do not have the protective covering that daguerreotypes have (http://www.knaw.nl/ecpa/sepia/workinggroups/wp4/guidelines.html).
Print source:
Schimmelman, Janice G. The Tintype in America 1856-1880. Philadelphia: American Philosophical Society, 2007.
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