@PaCo @Manuel Gozalbes @Felipe
Dear Margareth
Interesting questions and complicate to determinate general rules to define if one format is better than other.
I'm not a super expert about that, I have some experience and I need analyse the evolution of formats to be implanted it inside Dédalo.
As you comment TIFF has been the main format for preservation for years, why? I thinks that is a combination of lots of things.
I share with you the guideline of FADGI group about the formats:
https://www.digitizationguidelines.gov/guidelines/FADGI_RasterFormatCompare_p1_20140902_r.pdf
As you can see, is necessary a combination of parameters to take account.
TIFF and JPEG2000, data that is lost is not recoverable,
Yes, when you data is lost is not recoverable (remember to do backups!!! ;-).
But, one thing is clear for me. In the perspective of preservation any kind of compression is a bad way, lossless included. (of course, lossy compression has to be totally avoided ), why? lossless implies that the blocks compressed need to be analyse together and an error in a bit will destroy the block instead only the bit. So, to preserve data is better to save ir as uncompressed data, as raw data. And JPEG2000 has not option to save uncompressed data, and yes, save uncompressed data needs more space, but, as you say, nowadays it's not a problem, hard drives are relative cheap, and uncompressed images with high quality are not a issue anymore.
I'm saying that JPEG2000 is a bad format... no, but if you want to preserve your image file long term you need to take these things into account.
Have the arguments of file size and package sending error resilience, and iterative quality when loading an image over the internet just lost enough relevance that JPEG2000's advantages are just not significant anymore?
I think yes, is more important compatibility and raw data than network advantages when we talk about archival archives.
Other thing is the compatibility of the format, here JPEG2000 fails, it's not backwards compatible and this point is important if you want preserve your data.
In these case TIFF has a long life story, it's backwards compatible, and it has a robust format, so, when you want long term support you need compatibility.
JPEG2000 could be replaced by JPEGX? ( because it's backwards compatible )
https://ds.jpeg.org/documents/wg1n83043-REQ-JPEG_XL_Use_Cases_and_Requirements.pdf
JPEG2000 is easily transformed into other formats for different use cases
Well, I think that this point not realy true... both can be transformer to others formats easily
And are the limited browser support and encoding processes by now seen as not worth the effort, so that TIFF is the preferred format?
Yes, in fact JPEG2000 has not widely support into the image tools and his adoption is far to be fully implemented. Yes, some industries use it as medical professionals for MRI, X-ray, and CT scans, or digital cinema (remember the origin of JPEG as audiovisual format).
And what about sharing? well, TIFF is a large image file to be shared and not supported by browsers, here JPEG2000 wins... or not...
I think that preservation and sharing are different perspectives and it can not be mixed. When you want share the size and the compatibility between devices is the main thing, in preservation stability, compatibility, quality are more important than size.
And another format are arising for sharing as avif:
https://aomediacodec.github.io/av1-avif/
In nutsel;
- I think that TIFF remains as very good format for preservation.
- RAW storage preferible than compression.
- Other formats as JPEG2000, AVIF, JPEGXL could be a good options for sharing.
And other things to think: What profile use to preserver images?, which resolution? 8, 16 or 32bits per chanel?
Discusion is open!
@Manuel Gozalbes : can you invite to Angel to join us in this discussion?
Alex