Resizing Images for Alamy Using Photoshop at nugar.com

Resizing Images for Alamy Using Photoshop

The purpose of this document is to try and shed some light on the process of upsizing images for Alamy. This, as a lot of people seem to be confused and asking the same question over and over. Let’s begin…

Definitions

To fully grasp the process, we first have to get some definitions for the purposes of this document:

Image size: Is the pixel size of your image as seen when opened in Photoshop or any other image editor or viewer. For example, the native image size of a picture produced by the Canon 20D is 3504 x 2336 pixels. If you do multiply that results in: 8,185,344 pixels or 8 MP (Megapixels).

File Size: Is the “weight” of your file as seen on the Windows Explorer (or the file explorer on the OS of your choice).

Resolution: As used in Photoshop, this refers to the number of pixels per inch. This is purely a printing reference value, as a digital image will have a defined number of pixels regardless of what this field says.

Note

This process should be done as the last step of your workflow and with your image at 8 bit.

The process

So let’s say we have an image which is 3504 x 2336 pixels. We open it in Photoshop and go to the Image > Image Size menu. We’ll get a window like this one:

We can see three areas: Pixel Dimensions, Document Size and Resampling area.

The Pixel Dimensions area tells us, well, the pixel dimensions of the image, in this case 2336 x 3504 pixels, as it is a vertical image.

The document size area shows us that this image will print, when printed at a resolution of 240 pixels per inch, at a size of 9.732 in x 14.598 in. Alamy want us to sumbit images that are upsized to pixel dimensions of at least 48mb at 300 pixels per inch.

The important thing here is that this refers to the pixel size and not the file size.

So what do we do first? The first thing would be to set the resolution to 300, but without changing the image size at this time. So we un-check the Resample Image box:

And set the resolution to 300:

We press OK and the re-open the dialog box, going again to the Image > Image Size menu.

You can note several things here:

The Pixel Dimensions didn’t change. This is because we un-checked Resample Image. This is what we wanted.
The Resolution now reads 300 pixels/inch as Alamy asks for.
The printing size changed. It is now 7.787 in x 11.68 in. Actually, the resolution of the print media varies a lot, so this is just a guide.

Now let’s check again the Resample Image checkbox:

We will now resize or upsize the image to comply with the 48MB pixel dimension that Alamy asks for.

An easy way to do this is to change the Width and Height units from pixels, to percent:

Now, when we change the percentage, the Pixel Dimensions will (of course) change, let’s see:

We’ve changed it to 140%. Now we can see that the Pixel Dimensions have changed. From 23.4M to 45.9M. Are we good to go? No, because Alamy asks for at least 48M and this image would be rejected.

So we try another number:

Now, as you can see, the Pixel Dimensions are 52.7M. Are we good to go now? Yup! It now exceeds what Alamy asks for. If you want it to be *exactly* 48MB as Alamy asks, you can play with the percentage value.

Now, the image size complies with Alamy requirements. And, no matter what format you save it in, the image size will be what you see in this dialog box.

The File Size will vary, but the Pixel Dimensions are what matters.

By the way, using percentages instead of pixel values when resizing allows you to write an action for batch resizing. That way, you’ll never forget to upsize one of your images, which would cause a whole submission to be rejected.

Conclusion

I hope this brief tutorial helps with upsizing images for Alamy. If you have any question, please write me so I can answer it right here and benefit other photographers.

Written by Nugar

December 29th, 2007 at 9:29 pm

Posted in Alamy, General

15 Responses to 'Resizing Images for Alamy Using Photoshop'

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What a great tutorial! Thank you for making it so clear. One thing I don’t yet understand. Why do you need two steps, to change the resolution, before you change the image size? Why not do them at the same time?
Thanks and happy new year.

ahengst

1 Jan 08 at 11:58 pm
I change the resolution before changing the image size because we’re not actually changing the resolution, but only the way it is expressed. If we change the size and the resolution at the same time we risk Photoshop resampling our image.

Cheers, and Happy New Year to you too.

admin

2 Jan 08 at 7:22 am
That makes sense. Thanks!

ahengst

3 Jan 08 at 3:54 pm
Thank you for the good tutorial. I have to work a lot with image resizing at my work so I’m telling you it’s pretty hard to get to understand tools like Photoshop and I am really grateful for people who take it from the basics .What I also found and want to share with you is a great resizing tool with high quality results and a great price. You can find it at http://reshade.com where you can see it has some advantages over Photoshop. I must confess I still use Photoshop because some of my clients insist on it but, if I were to choose I would definitely choose Reshade.

Resizer

1 May 08 at 2:11 pm
Thanks for taking the time to explain this is such a straightforward fashion. Much appreciated from people like me who have so much still to learn. Muchas gracias

FatSprat

5 May 08 at 11:36 pm
Great tutorial, This topic has been bugging me for quite a while. I have a couple (3) of questions and I apologise before hand if I am being a pain in the $%^&.

1. Can I use this upsizing method on any size of pic, eg: will it look shabby if there is too big a hike in the upsize ? Say from a 1688 x 2376 (1.52 mb. )
2. You mentioned something about Batch uploading ? Have you created a tutorial on this to help ?
3. Off the topic slightly, are you able to explain your workflow when working with RAW files, eg: do you leave the original alone and just creat a jpeg to work from etc ?

Once again, thanks for a great tutorial.

bene07

17 Jul 08 at 8:58 pm
Hi Ben,

1. You can use it, but I don’t think the results will look good.
2. There’s a tutorial on this at Alamy’s site: http://www.alamy.com/contributors/stock-photography-submit.asp
3. Working with RAW is a HUGE topic. The beauty of it is that you can tweak a lot of variables and the file can always be returned to it’s original state. I don’t create a jpeg because each time you save a jpeg, you’re losing detail, so I work either as TIFF or PSD. I keep a copy of the PSD as Masterfile and at the last possible moment, convert to jpeg to upload to Alamy or to any other agency.

Hope this helps.

Cheers,

Nugar

Nugar

17 Jul 08 at 9:51 pm
That’s a neat tutorial, Nugar, and thank you for it. It works like that in Photoshop Elements 6, too (and possibly earlier editions of PSE).

However, I’m still confused about the size units Alamy is using. In its main statement of requirements, it says it wants “Uncompressed file sizes of more than 48MB…”*.

Your tutorial is based on their wanting files of at least 48 million *pixels* in size, not bytes. These are, as you know, different things.

(Even then, at one point you say: “If you want it to be *exactly* 48MB as Alamy asks, you can play with the percentage value.”. Perhaps it was a typo.)

I don’t want to risk having files rejected because they’re the wrong size, so what’s the answer?

Regards,

Roger

*See http://www.alamy.com/stock-photography-guide.asp .

RogerGW

2 Aug 08 at 1:37 pm
Hi Roger,

Yes, thinking about it, there’s a huge confusion about this topic. Alamy asks for 48MB in their site.

In any case, the technique still applies for the interpolation and no it wasn’t a typo. If you want the value of the pixel dimensions to be exactly 48M (well, yes M and not MB) you can play with the percentage in the Width and Height boxes.

Cheers,

Humberto (Nugar)

Nugar

2 Aug 08 at 2:23 pm
I forgot: here’s a page with some interesting info about what is a pixel in bits and bytes terms: http://www.scantips.com/basics1b.html

Cheers,

Humberto

Nugar

2 Aug 08 at 2:25 pm
Thanks, Nugar.

Further reading has unearthed this handy tip, which is to set the long side of an image to 5100-5200 pixels. That gives the requisite size, providing there’s been no extreme cropping.

Regards,

Roger

RogerGW

2 Aug 08 at 4:59 pm
Yes, that gives the size. Now, if you want to make a photoshop action to do some batch resizing, it is easier doing it by percentage and not by exact number of pixels.

If you want to do it by pixels, you can use the image processor in PS, but you have to remember going into the Preferences and set the Bicubic Smoother option as default method for upsizing.

Cheers,

Nugar

Nugar

2 Aug 08 at 6:25 pm
> Now, if you want to make a photoshop action to do some batch resizing, it is easier doing it by percentage…

Good point. Unfortunately, one can’t create actions in PSE (but you can use those made in full PS). You also can’t set a default method of changing image size.

Adobe need to justify the price differential somehow.

Incidentally, I’ve found a handy size-checker tool, here — http://www.braeside.plus.com/photography/alamy/alamy.html . It works in Windows or Mac O/S.

Cheers,

Roger

RogerGW

3 Aug 08 at 3:52 am
You can’t? It’s been a long time since I’ve used PSE…

About the software, it looks interesting. I’ll link it.

Cheers,

Humberto

Nugar

3 Aug 08 at 6:16 am
Never could, as I recall.

Roger

RogerGW

3 Aug 08 at 10:00 am