From one or more of your local photos, obtains subsections from each photo giving a range of circular png images and horizontal rectangular jpg images
This is a shell script specific to bash.
This creates a series of non-overlapping horizontal rectangular subsections from local JPG images in the working directory. In addition it creates a series of circular png images suitable for profile image placeholders. The resultant 2 new sets of images are placed into new directories. This script uses imagemagick.
To check if you have imagemagick, type man convert and the manual will come up if you have it. If it doesn't come up, you can install imagemagick using your Linux package manager.
This is helpful for those who want to quickly and easily generate a series of simple images perfect for quick mock-ups or as a source of images for generative fiction.
These images do not look fancy but are ideal for when you just need to generate multiple simple and non-meaningful images quickly.
All you need is the shell script from this repository photosubsec.sh and your own image file(s) - as many or as few as you want, whose filenames start with IMG and end with .JPG or .jpg.
The remainder of the files in this repository are example input and output images.
To use, place this script in the same Linux working directory as your source image files. Ensure the script has executable permissions. At the command line, type './photosubsec.sh' (without the quotes). No arguments are needed; the script will act on all images in the working directory which start with IMG and end with .jpg or .JPG
This creates directories 'SUBSEC-horizontal' and 'SUBSEC-profile'; be aware that if these already exist inside your working directory they may be overwritten. Your horizontal jpgs will be placed in SUBSEC-horizontal and the circular pngs suitable for profile images will be in SUBSEC-profile.
This script uses whatever images you have in the working directory where you're running this script. (Note: it actually uses images that start with IMG and end with .jpg or .JPG since that's how most camera images are formatted - of course, you can adjust the script to your own needs). The advantage of using your own images is that you then don't need to worry about spending time to find public domain images, etc.
This repository shows example input and output. The 3 JPG files in the main directory are the input photos (taken by me). The 2 SUBSEC directories contain the output images. This allows you to get a feel for how it works before trying it with your own photos.
Source images are best suited when they are in landscape format and approximately 2400x1600 but the script works well on other sizes and aspect ratios. Do not worry about not having the exact size or the aspect ratio; this is all taken care of by the script. It will still work with images other than the recommended size or different aspect ratios, but in those situations be aware some parts of your source photo will never get used (small-ish bits on the right and on the bottom) and/or there will be some lossiness in the resultant new images (originals remain unmodified). The degree of lossiness you experience is proportional to how far away your dimensions and aspect ratios are from 2400x1600. Your aspect ratio is always maintained, it's just that scaling of your photo as a whole might be applied during the process (again, without modifying the original).
This script is particularly well suited to modification for other purposes and use cases, for example extra image processing to add artistic effects and/or output of other dimensions of images.
If modifying this script, be aware that the tiling process (i.e. cropping with adjoin) is best with an exactly divisible number of the desired cropped tile size versus the whole image as resized in the script (here 2400x1600). The script as written ensures an exactly divisible number, but if you are modifying dimensions please pay attention to this issue. This will still work with a non-divisible tile size, but in that situation some tiles (those from the edges of the image) will be smaller in one or both x/y dimensions than your specified size, since those are the leftover slivers that don't add up to a full tile unit. So aim for exact divisibility of tile units. This is only a concern if you plan on modifying the script.