This is the guidance Alamy themselves provide on whether or not to upsize: "Clearly a high quality 48+MB file is still the ideal solution for customers, it offers the full range of file sizes and gives end users greater scope. There is no need for you to change your workflow if you don't want to. The difference now is that it's not a mandatory requirement for the images to be at that size, we will leave that decision up to you."
There's a lot going for Alamy as a rights managed stock photo agency--especially for those focusing on editorial images--but upsizing and rsesizing images for Alamy can be a pain. Alamy will only accept images that equate to a 48MB uncompressed 8-bit RGB file (see Alamy's submission guidelines here), which is intended as the digital equivalent of an 11x18 inch print. That means that if you use a camera with less than 16-megapixel resolution, then you'll have to upsize your images. (This is not the place to discuss whether Alamy should be asking for files that are potentially degraded by upsizing. The simple fact is that they do, and this is a way to work with that.)
But there's also a gotcha with those working with cameras with significantly higher resolution, such as some of the newer top-end professional DSLRs that have a resolution of 20+ megapixels, or if you work with stitched panoramas which can easily get up into the 30- to 40-megapixel range. In theory, there's no upper limit on the size of the images you submit, but in practice now that Alamy has switched mostly to its web uploader rather than the old (and slow) system of sending DVDs of images, the top limit is a 25MB JPEG file saved at Photoshop quality level of 10 or above. A 30-megapixel panorama saved at a quality setting of 10 will likely exceed 25MB.
Resizing images for Alamy, therefore, is not just about upsizing but can also mean downsizing. Most file resizing tools let you set the target dimensions or longest edge, but few let you aim for a specific filesize. Some let you specify a resulting file of a specific number megapixels (a 16 megapixel image creates an uncompressed RGB 8-bit file of around 48MB).
If all you ever work with are images of the same dimensions and aspect ration, it's easy enough, through a little trial an error, to settle on resizing dimensions that will work. With a standard 4:3 or 3:2 ration image, fitting your image in maximum dimensions of 5100 x 5100 pixels will get you close in most cases (see the example here, for instance). That works well enough for images with a standard out-of-the-camera aspect ration, but throw in some images with non-standard aspect ratios (panoramas, square frames, or even just cropped images, for instance) and it can become tedious quickly. So if you work with a mix of standard frame originals and panoramas, it's handy to have a process that manages both upsizing and downsizing, producing a 48MB file regardless of whatever image you feed into it regardless of aspect ratio or image size.
If you use a Mac, you can take advantage of the infinitely handy Automator tools to make the whole process, well, automatic and end up with perfectly sized files every time without the trial and error of other methods. And better yet, it will work comfortably with as many files as you wish to throw at it, whether that's 1 or 1,000. And you'll end up with perfectly resized files ready for uploading.
There are, however, some prerequisites.
- Firstly, you'll need Mac OS X 10.4 or above. That was the first version that included Automator baked in. I'm not going to go through the basics of working with Automator. For those who have never worked with Automator before, you will likely find the video "Intro to Automator" useful; it's accessible from the top right of this page on Apple's site.
- Secondly, you'll need Adobe Photoshop. I'm focusing on here on CS5 and CS4; your mileage might vary on earlier versions.
- Thirdly, you'll need Ben Long's excellent Photoshop Automator Actions. Previous versions used to be donationware, but the latest version (5.0), required for CS5 compatibility, is released in two versions: a free version and a "pro" version for $19.95. For the process outlined in this post you'll need the "Resize to File Size" action, which is only available in the pro version. But for your money you'll also get a bunch of other extremely useful actions that can save you oodles of time.
Once you've got all those sorted and you've downloaded and installed Photoshop Automator Actions, we're ready to put them to work. But before we get started, please note that the workflow below assumes you are working with 16-bit TIFF exported copies of your images that you've already exported from your RAW processor of choice (Lightroom, Aperture, Bibble, C1, etc) at their original image size. I strongly recommend that you not apply this Automator workflow on your original images. Make copies and use those copies. And there are a number of places in this workflow where variations are possible but will still lead to the same end result, so you can tweak this process to accommodate any particular needs or preferences you have. You could, for example, add color profile conversion or choose a folder each time you run it.
Creating the Automator Application
In Automator, create a new Workflow or Action. It doesn't really matter at this point whether you choose Workflow or Action, because you can save them both as an Application later.
From the available Actions in your Automator Library, add these Actions. They should be arranged in this order:
- Get Specified Finder Items
- Get Folder Contents
- Filter Finder Items
- Resize to File Size
- Change Bit Depth
Now that those actions are arranged in the workflow in that order, we're going to set the options. Firstly, in the Get Specified Finder Items action click the "Add..." button and specify the folder containing the images you want to resize. While you can technically change this each time you run the workflow, I designate a specific folder that I use just for this workflow. Again, I strongly recommend that you work with copies of your images, not originals.
There are no options to set in Get Folder Contents, so go straight to Filter Finder Items. I only want to run this on TIF files; if it's set to JPG you risk creating an endless loop. Using TIF files will also have advantages when we put it all together with exporting from the RAW editor. So set the options to "All" "File Extension" "contains" "tif".
There are no options to set in Open, so go straight to Resize to File Size. This is the magic ingredient in this workflow and one of the many reasons Ben Long's set of Photoshop Automator Actions is so valuable. If you're resizing 8-bit TIF files, set this to 48mb. If you're working with 16-bit TIF files, set it to 96mb as I've done below. The reasoning is simple: an uncompressed 16-bit TIF is precisely twice the file size of an uncompressed 8-bit TIF. I set the resolution to 300ppi, but this setting is irrelevant unless you're dealing with prints.
Now that the file has been resized, we need to change it to 8-bit so that we can save it as a JPG. Set the Change Bit-Depth to "8-bit."
Finally, we need to save the resized files to JPG so we can upload them to Alamy. In the Render action, click on JPEG.
- Check the "Save as JPEG" box.
- Leave the file naming options at the default unless you have reason to change them. Alamy applies its own file naming scheme.
- Set Format Options to either "Optimized" or "Standard" (it really doesn't matter for this).
- Check "Embed color profile" box.
- And, finally, set the "Quality" to 10, 11, or 12.
Finally, save your Automator workflow as an Application.
Voila! You should now have perfectly sized JPGs ready for uploading to Alamy. There are a bunch of ways you can tweak this process to fit your workflow. To run it on your images, you can drag and drop the images from Finder onto the Application's icon or, if you'd prefer to run it manually, add a "Ask for Finder Items" action right at the beginning of the workflow. If you use Lightroom, you can streamline the process even further.
One-Step Export and Resize Using Lightroom
The steps above start from 16-bit TIF files that have been exported from your RAW converter of choice. If you use Adobe Photoshop Lightroom, there's a handy export feature you can make use of to export and resize in one step by using the "Post-processing" function in the export dialog.
First, make sure that the Export Location corresponds to folder location you specified when creating the Automator application. In the "After Export" drop-down menu, choose "Open in Other Application..." and then choose the Automator Application you saved above. Then save it as an Export Preset.
Disclaimer: This is how I do it, but your mileage might vary. And be sure to use copies, not your original images.