An image archive is a place to store your photographic images in an organised safe place. In addition to this is good practise to create a number of backups of your photographic images in case of corruption, damage, theft, hardware failures etc. These backups may be local i.e. a local hard drive or a Cloud storage device.
ImgArchive helps you create an image archive from a set of unorganised images into an archive that is that is organised and fully backed up.
How this is achieved
ImgArchive has a list of all the Image type extensions both pictures and raw that are image types. For example JPEG have the extension “.jpg” Nikon raw files have the extension “.nef. ImgArchive scans the file system looking for image types. Once found is added to a list. Then once the scan is is complete ImgArchive then processes each file extracting the EXIF information and checking if the file has already been imported into the archive. If the check finds that the image Has been already imported then the duplicate is rejected.
How duplication checking is achieved -This duplication checking is carried out by using cryptographic checksums of each image imported into the archive. If two images have the same cryptographic checksums then it is cryptographically unlikely that the two images are not the same.
Metadata generation – Once this initial processing is done. ImgArchive creates a metadata file containing Information about each of the archived image. The source of this information can be from a metadata template, Or by reading the EXIF information.
The File Structure – The next step is to archive the images into a date organised file structure. This structure is very much like the structure you see in a phone gallery, Flickr also uses a similar date organised structure. The image capture date from the EXIF is used as a key. All images with the same day-date are stored in a folder. creating a set of folders in a year folder. The Archive is thus a simple year/day structure which is easy to understand and manage.
While carrying out this process image archive will check that there is no file name clashes. This will happen if two image file names have the same day date. In order to stop the second image overwriting the first, the second, will be automatically renamed with an index making it unique to that particular day.
Image Re-naming Optionally ImgArchive allows you to rename images in order to give them a more user friendly name.
Backing-up – Once archived the next stage is to optionally backup images to one or more online backups and optionally cloud storage backup.
Online storage is normally carried out using local or network drives which generally Have a fast access and write speed. Cloud storage on the other hand are generally much lower. To cater for this, cloud storage is generally backed up using a second background process which can then be paused and restarted if the Internet connexion goes down while the backing up process is being initiated.
Validation – This is the last step in the import process where All the backups Are validated against the master Thus making sure that all of the Image copies are identical and have been processed without Inconsistencies.
Accessing the Archive
ImgArchive Aims to protect your images as far as possible. One such way is to structure the archive into two parts The first part Is the vault. This is where the primary copy of your images are kept.
The second part is the user area or space. This space is where you have access to your Images. Whenever required you can request images to be copied from the vault into this space This can be a complete copy of all the images held in the vault or part of it.
If at any time images in the user space gets damaged, deleted, corrupted or whatever, a fresh copy can be brought from the vault overwriting, the damaged or deleted copy in the user space. Thus safeguarding your images.
The Vault
As mentioned before the vault is where the primary copies of your images are kept. Therefore special measures are taken to ensure the consistency of these images.
Validation – When images were imported into the vault a cryptographic checksum was taken of each of the images plus each of the metadata files associated with each of those images and stored in a separate checksum file.
At any time, The images stored in the vault can be compared against the checksum stored in the checksum file. If any of these differ then more than likely the image or metadata file is corrupted. If this is the case then the vault can be repaired by taking one of the images from the backup and use to overwrite the damaged image. Note that the backups contain checksum files to make sure the backups also can be validated.
Image Version control – Never manipulate your original media, i.e. the original image or images. Once the original is changed there is no way to revert to the untouched original its lost forever. ImgArchive supports versioning by coping images out of the vault into a user defined Workspace area for editing images. When you want to make changes to an image in ImgArchive you check the image out of the archive into the workspace for changes, once the changes are made you then check the image back into the archive. The changed version will be the current image in the archive but the original will be preserved in the archive untouched as the previous version. Each time you make a change a new version of the image will be made.
If you wish to go back to the original or a previous version of the original the you can check it out into the workspace. The original is safeguarded along with any changes you made of versions of the original which in them selves may have had a number of hours invested in them.
The Workspace is just an area on the hard drive where images can be worked on. It’s best practice to work on one copy of an image at a time.