How do I resize image of multi-folder file without resizeImage?

Question

(see background for context)

I don't need to resize the photoshop file I am working on but I do need to resize the optimised images I am exporting. My problems would be solved if ExportOptionsSaveForWeb had image size properties!

Background I have a Photoshop file to manage the weekly images I need to produce for a show. Each folder is a week and each week there are about 5-6 folders which contain the layers for that image. Each week I export the 5-6 folders into 3 images of different sizes and place them into different folders according to their size. I've explored: Generate Image Assets, Image Processor and recording Actions with no luck so I am now trying scripting.

Answer 1

You can do this pretty easily without all the complexity of Photoshop scripting by using ImageMagick which is installed on most Linux distros and is available for OS X and Windows.

The command to use is convert and you can put it in a Windows BATCH file or a small shell script on OS X. Say your completed, saved image is called image.psd, and you need to create 3 sizes - one in each folder of large, medium and small. The command would look like this:

convert image.psd[0] -resize 800x600 -write large/image.jpg  \
                     -resize 640x480 -write medium/image.jpg \
                     -resize 160x160 small/image.jpg

The \ are just line continuations, you can renove them and scrunch everything up together on one line - I just think it looks easier conceptually like I have written it.

If you started off with this image, that I examine using identify (also in the ImageMagick suite):

identify image.psd[0]

Output

image.psd[0]=>image.psd PSD 3675x4875 3675x4875+0+0 16-bit sRGB 1.1474GB 0.000u 0:00.000

you can see it is 3675x4875, and the smaller versions are as follows:

identify large/* medium/* small/*

Output

large/image.jpg JPEG 452x600 452x600+0+0 8-bit sRGB 195KB 0.000u 0:00.000
medium/image.jpg[1] JPEG 362x480 362x480+0+0 8-bit sRGB 166KB 0.000u 0:00.000
small/image.jpg[2] JPEG 121x160 121x160+0+0 8-bit sRGB 118KB 0.000u 0:00.000

P.S. Note that none of the above commands alter your original image in any way - they just create smaller versions of it.

P.P.S. If installing ImageMagick for the first time on Windows, or OS X, please ask for hints first...