File Formats
What format you use is dictated by your goal. Libraries have a tendency to want to have a small access copy of reasonable quality, and a high quality archival copy of reasonable file size.
To get a better idea of what the different formats are, and what they do, I've linked to some articles:
TIFF (Tagged Image File Format )
JPEG
JPEG2000
PDF
JPEG is the perfect format for full color or grayscale images because it provides a nice balance between quality and file size. The format is stable as long as you do not edit the file over and over. If you are going to be editing the file, save it as a Tiff first, then save it as a JPEG. JPEGs are perfect for access copies, and sometimes for Archival copies.
A full color or grayscale Tiff is huge as far as file size goes. A black and white Tiff, however, is generally smaller than a black and white JPEG. Don’t ask me why. Tiff also provides the best quality and stability. You can use Tiffs for archival storage if you have a lot of storage space and not a lot of items. However, if you are strapped for storage space and have lots of items, go for JPEG.
A PDF is a good delivery format becasue it is a format that can be vewied the same on different computers, and if there is OCRed text involved, it can contain that text and offer it to the patron in a format that is familyer.
Lossless vs. Lossy formats (Abriviation of Color)
The Reason why Jpegs and Tiffs are different is that Jpegs are generally lossy (they lose or truncate some data- making the file size and quality lower) and Tiffs can be either lossy or lossless (each pixel’s data is recorded- making the quality better and the file size much larger).
Why no other formats matter:
Other formats (Gif, Bitmap, etc.) often fall short of one of the two conditions (either they don’t have enough quality, or they require too much memory space for the quality that you get).
You may want to look into JPEG 2000, because the format supposedly takes the best parts of a JPEG (small file size for the quality) and Tiff (uncompressed information), and serves it up in one complete package. However, look into it before you use JPEG 2000 because it has not been fully accepted by the information community and it might not be widely well known to your users.
What format you use is dictated by your goal. Libraries have a tendency to want to have a small access copy of reasonable quality, and a high quality archival copy of reasonable file size.
To get a better idea of what the different formats are, and what they do, I've linked to some articles:
TIFF (Tagged Image File Format )
JPEG
JPEG2000
JPEG is the perfect format for full color or grayscale images because it provides a nice balance between quality and file size. The format is stable as long as you do not edit the file over and over. If you are going to be editing the file, save it as a Tiff first, then save it as a JPEG. JPEGs are perfect for access copies, and sometimes for Archival copies.
A full color or grayscale Tiff is huge as far as file size goes. A black and white Tiff, however, is generally smaller than a black and white JPEG. Don’t ask me why. Tiff also provides the best quality and stability. You can use Tiffs for archival storage if you have a lot of storage space and not a lot of items. However, if you are strapped for storage space and have lots of items, go for JPEG.
A PDF is a good delivery format becasue it is a format that can be vewied the same on different computers, and if there is OCRed text involved, it can contain that text and offer it to the patron in a format that is familyer.
Lossless vs. Lossy formats (Abriviation of Color)
The Reason why Jpegs and Tiffs are different is that Jpegs are generally lossy (they lose or truncate some data- making the file size and quality lower) and Tiffs can be either lossy or lossless (each pixel’s data is recorded- making the quality better and the file size much larger).
Why no other formats matter:
Other formats (Gif, Bitmap, etc.) often fall short of one of the two conditions (either they don’t have enough quality, or they require too much memory space for the quality that you get).
You may want to look into JPEG 2000, because the format supposedly takes the best parts of a JPEG (small file size for the quality) and Tiff (uncompressed information), and serves it up in one complete package. However, look into it before you use JPEG 2000 because it has not been fully accepted by the information community and it might not be widely well known to your users.
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