This tutorial was written after seeing another tutorial on resizing images to comply with Eurobricks standards as explained in the Site Guidelines.
I thought it would be nice to increase exposure to this great program that is available for free from Google; the program runs on most major platforms, including Windows, Mac OS, and Linux (which is what I'm using to right this tutorial).
Picasa is a photo organizing program that has extended features, including resizing, cropping, straightening (arbitrary rotation, not limited to 90 degree increments), color enhancements (lighten, darken, contrast, and a handful of special effects).
When run, Picasa scans your directories for images... you can limit which folders it searches (Tools->Folder Manager), but I don't want to go into any features that aren't useful for the topic at hand.
tutorial_01_overview by FredJH, on Flickr
This is how Picasa looked when I ran it on my computer (I restricted folders for this tutorial). In response to a question on bricklink about what to do with the Figure Skater's skates when she's being displayed, I took this picture and uploaded to show you could display with the figure wearing them (you can use this for a lot of the new collectible minifigures, but I digress).
Double-click on the image to edit it; you get a window like this one:
tutorial_02_edit by FredJH, on Flickr
The pane on the left shows three groups of editing functions, starting with Basic Fixes. For the purposes of this tutorial, we'll stick with using just the basics, but here are the options just so you can see what's there:
tutorial_04_tuning by FredJH, on Flickr
tutorial_05_effects by FredJH, on Flickr
You can see what's nice about the effects is you get a little tiny preview of the effects the tools will have on the image you're working on.
IMO, the first thing you want to do is straighten out any crookedness in your image. My image is pretty straight, but I clicked on "Straighten" anyway to show how it works.
tutorial_03_basic_fix_straighten by FredJH, on Flickr
You get a helpful grid to help you make sure your image is straight; the slider at the bottom rotates by degrees. When you're done, click "Apply."
NOTE 1: It's important to do straightening BEFORE cropping, as you necessarily lose some of the picture (the corners) as they rotate out of the frame.
The next step (labeled 1) is Auto Color... as Google often does, they've made the default settings really quite useful, as I've been able to fix most pictures simply by selecting I'm Feeling Lucky, but all this picture needs is some color correction (I'm still reading books on how to use my fancy-smancy camera, this seems to be one of my bigger problems). As you can see (compare to the images above), a simple click of Auto Color fixes up this image quite nicely.
tutorial_06_auto_color by FredJH, on Flickr
NOTE 2: It's important do to automatic color corrections BEFORE resizing and cropping... why? Because the larger image gives Picasa more data to work with to figure out what's wrong.
Next we crop the image (labeled 2 in the above image); pushing the "Crop" button brings us to the following screen:
tutorial_07_crop by FredJH, on Flickr
Eurobricks guidelines specify 800x600 maximum resolution (which is what most of these images are). That's a 4x3 ratio, as is the lower resolution recommendation of 640x480. So, instead of awkwardly trying to get it right with the manual setting, we're going to tell Picasa we want a 4x3 ratio so that when we do resize the image it will match perfectly the recommended resolutions.
tutorial_08_crop_aspect by FredJH, on Flickr
This is going to seem like a waste of an image, but take a look now under where you select the aspect... there are three "automatic" choices for cropping. The center one is actually very close to what we want, but we're not going to take the easy way out for the sake of demonstrating:
tutorial_09_crop_auto by FredJH, on Flickr
Now that you've selected the aspect, you can go into the image window and drag a rectangle around the area of the image you want to crop to. The major features here are that if you drag a larger width than height, it's automatically landscape oriented, and if you drag a rectangle taller than it is wide, it's automatically portrait - but it always remains a 4x3 aspect. Once you've drawn the rectangle, you can reposition the entire rectangle by clicking in the rectangle and dragging. You'll also see the corners highlight boxes you can grab to resize the rectangle:
tutorial_10_crop_landscape by FredJH, on Flickr
tutorial_11_crop_portrait by FredJH, on Flickr
Once you're happy with the crop, select Apply, and you will end up with something like the following:
tutorial_13_crop_after by FredJH, on Flickr
Now we're ready to export the image resized to what we want it. Go back to your image library by clicking Back To Library, and from the file menu select "Export Picture to Folder." Keep in mind, your image library actually allows you to select multiple images and you can export them all at once, resizing them all to the same size in the process.
tutorial_14_export by FredJH, on Flickr
The dialog looks like this:
tutorial_15_export_options by FredJH, on Flickr
Here you specify the output folder (pick something different than the directory the images are in, IMO), and we select 800 as the size - that's the maximum dimension, so it doesn't matter if your picture is wider or taller - the largest dimension will be 800. Since we selected a 4x3 aspect when we cropped the image, the other dimension will automatically be 600, resulting in a 600x800 image. If our image was wider than it is tall, it would be 800x600... you don't have to do anything other than tell it the maximum dimension.
After clicking on OK, Picasa processes the image (or images) and opens up the folder for you automatically. On my system, this is what I get:
tutorial_16_export_folder by FredJH, on Flickr
Uploading to flickr or brickshelf is left as an exercise for the reader! However, Google offers Picasaweb, a place like the other image services with free online storage space and direct linking/embedding like I did with flickr in this tutorial. Picasa has integrated features for uploading directly to your picasaweb account.
I presented a very basic walk-through of preparing an image for use with EB; Picasa itself is quite simple to operate, but gives you a number of features for fixing up images and adding special effects. To do really fancy/advanced editing, there is another free software package called The GIMP (Gnu Image Manipulation Program). It's a photoshop "clone" with many of the features found in photoshop, and is also available on all of the major operating systems.
Please let me know if you find this useful or if something is unclear.
There are features that I have not covered that many may find of interest; Picasa can be an all-in-one application (completely free and multiplatform) to organize your photos (including tagging images, which is a nice feature when searching through a large collection), including batch processing, text annotation, and a number of special effects. It's simple to use, includes features you may not need for LEGO but which are still quite useful (like red-eye reduction). Please let me know if you'd like to see a tutorial on any of these other features.
Edited by fred67, 20 April 2011 - 03:30 PM.