Creating a grid or template for images to fit into

Creating a template for a Web page layout is simple. All that is needed is a Background layer and an Alpha channels that map each Image's Location Size and Shape.  These templates can be autocratically or interactively populated using a Photoshop scripts. Populated  templates will be layered documents that can be easily modified using Photoshop and saved for use on your web pages.

Photo Collage Toolkit

Photoshop scripting is powerful and I believe this package demonstrates this here is a video showing a 5 image collage PSD template  being populated with images

The package includes four simple rules to follow when making Photo Collage Template PSD files so they will be compatible with my Photoshop scripts.

1. Size the photo collage templates for the print size you want - width, height and print DPI resolution.
2. Photo collage templates must have a Photoshop background layer. The contents of this layer can be anything.
3. Photo collage templates must have alpha channels named "Image 1", "Image 2", ... "Image n".
4. Photo collage templates layers above the background layers must provide transparent areas to let the images that will be placed below them show through.

There are fifteen scripts in this package they provide the following functions:

1. HelpPhotoCollageToolkit.jsx - Online Help
2. TestCollageTemplate.jsx - Used to test a Photo Collage Template while you are making it with Photoshop.
3. CollageTemplateBuilder.jsx - Can build Templates compatible with this toolkit's scripts.
4. LayerToAlphaChan.jsx - Used to convert a Prototype Image Layer stack into a template document.
5. InteractivePopulateCollage.jsx - Used to interactively populate Any Photo Collage template. Offers most user control inserting pictures and text.
6. ReplaceCollageImage.jsx - use to replace a populated collage image Smart Object layer with an other image correctly resized and positioned.
7. ChangeTextSize.jsx - This script can be used to change Image stamps text size when the size used by the populating did not work well.
8. PopulateCollageTemplate.jsx - Used to Automatically populate a Photo Collage template and leave the populated copy open in Photoshop.
9. BatchOneImageCollage.jsx - Used to Automatically Batch Populate Collage templates that only have one image inserted. The Collage or Image may be stamped with text.
10. BatchMultiImageCollage.jsx - Used to Automatically Batch Populate Any Photo Collage template with images in a source image folder. Easier to use than the interactive script. Saved collages can be tweaked.
11. PasteImageRoll.jsx - Paste Images into a document to be print on roll paper.
12. BatchPicturePackage.jsx - Used to Automatically Batch Populate Any Photo Collage template with an image in a source image folder.  Images Rotates for best fit.
13. BatchPicturePackageNoRotate.jsx - Used to Automatically Batch Populate Any Photo Collage template with an image in a source image folder.
14. PopulatePicturePackage.jsx - Used to Automatically populate a Photo Collage template Fill with the same single image and leave the populated copy open in Photoshop.
15. PCTpreferences.jsx - Edit This File to Customize Collage Populating scripts default setting and add your own Layer styles.

Documentation and Examples

Is the layout going to be the same every time? I create templates for digital scrapbooking all the time. Just use clipping masks over a shape to drop on your images.

A Script can tile out image and fit your imagest to the tile size you want to use.

http://www.mouseprints.net/old/dpr/PasteImageRoll.jsx

http://www.mouseprints.net/old/dpr/PasteImageRoll.html

I _think_ our JJMack has a script that does it automatically on his Mouse Print website.  He'll be along to clarify before too long.

JJmack's Image Visualization

You could use View > New Guide Layout to set up guides.  You can save various Presets via the drop-down (where it says preset)

When you Free Transform your images, they will snap to the guides.  Remember to hold down the Shift key when Transforming to maintain the aspect ratio.

If images do not fit the guide layout perfectly in vertical or horizontal, then Smart Guides will help you line things up, (the pink lines).  Note they have to be turned on in ​View > Show​.

Thanks for the suggestions. All images are the same size. I just want to make them into a row of three

Maybe ImageProcessor.jsx is also helpful.

Record an action. The exact steps in the action depend on what exactly you want.

If you just need them to be the same pixel height, use File > Automate > Fit Image. Set height as required and width to some arbitrary high value.

If you need them to be exactly the same height and width, they must first be cropped to the correct aspect ratio. You can do this with the crop tool set to ratio. If part of an action, tick the dialog icon in that step. This pauses the action so you can position the crop - hit enter and it continues.

Then the pixel dimensions can be set either with Image Size, or in the Save For Web dialog if you prefer to use that.

If convenient, set up a dedicated folder and save to that as part of the action.

You can use Smart Objects - but it's not to easy

Just prepare a new document with destiination width, height and resolution - it will be your tempate

Drag your first image from system widnow into your PS document. Adjust size and position and press Enter to confirm it

Drag second and third image and adjust size and position the same way.

You can add any effect or transform to these images

Save all as Photoshop document

Now if you want to change your images just select right layer (Layers Panel) and use right mouse to choose Replace Contens command

If you need you can adjast size of this graphic

You can also use External Smart Objects

pawel

Can you give us more informations:

images that you want to line up are always with the same dimensions, resolution and orientation or not?