General ComputingProtecting Data Against Malware

Copying Photos to a Tablet

[Posted on: 12 July 2015]

I have always been very hot on backing up computer data, even to the extent that when taking a camera on holiday I like to be able to back up my pictures to a separate device on a daily basis in case anything goes wrong with the camera or memory card. I have always resisted the idea of taking a laptop on holiday as computing is my livelihood and the laptop constitutes too much of a work item! As a result, when we got an iPad I bought a camera dongle to transfer photos on to the device from the memory card. Whilst this fulfils the need to back up the pictures and also makes them available for instant viewing, I find the whole setup on the iPad very user unfriendly in terms of organising and managing photos compared to a traditional desktop platform, added to which I have also found the camera dongles to be somewhat temperamental at times.

So maybe it is better to take the laptop away after all as a backup device, but even so it is good to be able to transfer the photos on to a tablet for viewing. As well as the iPad I now also have a Kindle Fire, an Android based device.

If photos are to be initially stored and organised on a computer, how then do we go about transferring them to a tablet? I’ve actually found it to be very easy, but there are a few useful things to consider.

File sizes. A tablet device will typically have much less storage space than a computer. At the same time a photo from a modern digital camera will have a pixel count much bigger than a tablet screen. For example a 12 megapixel camera with a 4:3 ratio will generate images of 4000×3000 pixels, whereas a full size iPad screen is only 2048×1536 pixels (i.e. only about 26% the size of the 12MP image). It would therefore make sense to reduce the size of each image for the purpose of uploading to a tablet. Personally I use IrfanView, which has a very good batch processing facility included, and it is free. I have always found that when saving JPEG images for screen viewing, saving at 90% quality gives a good compromise between storage size and quality.

Copying and syncing. On the Kindle Fire it has proved very simple. Just copy folders of photos from the computer directly into the “Internal Storage/Pictures” folder on the device and albums will immediately appear in the photos section with names corresponding to those of the associated sub-folders. With an iPad, the same can be done in principle but not by the same method of directly copying the folders. Instead you will need to use iTunes to carry out the synchronisation, but the end result is basically the same.

Photo order. The photos should normally display in chronological order (i.e. by date/time taken) and this is done using the Exif data from the files (standard metadata tags held in an image file). After uploading my photos I initially found that in some of the older albums there were a number of photos out of order. On further investigation it turned out that the offending items were those pictures that happened to be taken in portrait mode. This is because at the time, the images had been rotated by a method that caused the Exif data to be lost. Very frustrating but all is not lost. Exiftool is a very handy tool for editing the Exif data in a file. It is a command based utility and I have a written a small DOS batch file (download here) that uses it to resequence all the JPEG image files in a given folder. The batch file works on the assumption that the filename sequence matches the chronological order of the photos (likely to be the case more often than not). On running it you need to specify the folder and provide a date and base time. The image files are then all resequenced in one second increments. The batch file can easily be modified to do things differently if required. (N.B. The DOS command prompt still exists on the more modern versions of Windows!)

Hope there are some useful hints here. Enjoy your photos.

General ComputingProtecting Data Against Malware