Wallpaper-splitter is an application for splitting large images up into smaller images to be used for desktop backgrounds.
Every program is created to scrach an itch. In my this case, I was getting really tired of using GIMP to break large wallpapers apart. My monitor configuration is non-standard and my monitors are not all the same size. I wrote wallpaper-splitter to easily break my wallpapers apart so I can apply them on individual monitors to form a unified image. Hopefully it can help you do the same.
First you need to make a monitor definition JSON file. An example is shown here:
{
"comment": "Inverted T composed of 4 1920x1200 monitors",
"monitors":
[
{"name": "Top",
"resolution": [1920, 1200],
"upper_left": [1920, 0],
"suffix": "_1"
},
{"name": "Left",
"resolution": [1920, 1200],
"upper_left": [0, 1200],
"suffix": "_2"
},
{"name": "Middle",
"resolution": [1920, 1200],
"upper_left": [1920, 1200],
"suffix": "_3"
},
{"name": "Right",
"resolution": [1920, 1200],
"upper_left": [3840, 1200],
"suffix": "_4"
}
]
}
The resolution of each monitor should be given in pixels along with the coordinate of the upper left pixel. The coordinate system has (0,0) in the upper left in the form of (x,y). y grows positive as it grows down.
If this seems a little hard to visualize simply convert an image with wallpaper-splitter and it will print out a representation of the given monitor configuration. For example, lets use this example monitor definition file to split an image:
> python3 src/wallpaper-splitter.py -m \
> resources/monitor_defs/inverted_T_1920x1200.json image.jpg
Monitor Layout read from definition file:
+-------------------------+ +
|Top | ^
|1920x1200 | |
| | |
| | |
| | |
| | 2
| | 4
+-------------------------+-------------------------+-------------------------+0
|Left |Middle |Right |0
|1920x1200 |1920x1200 |1920x1200 ||
| | | ||
| | | ||
| | | ||
| | | ||
+-------------------------+-------------------------+-------------------------+V
+<-----------------------------------5760------------------------------------->+
Processing: image.jpg
Projection of monitor definition file onto image.jpg:
+
^
|
|
+-------------------------+ |
|Top | |
|1920x1200 | |
| | |
| | |
| | |
| | 2
| | 5
+-------------------------+-------------------------+-------------------------+6
|Left |Middle |Right |0
|1920x1200 |1920x1200 |1920x1200 ||
| | | ||
| | | ||
| | | ||
| | | ||
| | | ||
+-------------------------+-------------------------+-------------------------+|
|
|
V
+<-----------------------------------4096------------------------------------->+
>
Wall-paper splitter has the following dependencies:
- Python3
- Pillow (https://pillow.readthedocs.org/)
Wallpaper-splitter tries its best to overlay the monitor configuration onto the source image(s) provided. It tries to stretch the monitors as large as possible onto the image(s). It will either bump up against the left/right or the top/bottom of the image first. As soon as that happens, it figures out how many pixels on the image correspond to pixels on the monitor and then crops the image for each monitor. After that, it scales the images to match the output for each monitor wallpaper desired (unless told not to).
You have some control over how wallpaper-splitter decides where to chop the image apart. Imagine if you are trying to overlay a 2 monitor high monitor definition onto a very wide image. Wallpaper-splitter would be limited very quickly by the height of the image but would have a lot of freedom to choose from for the location horizontally to overlay. You can use the positional arguments to affect where wallpaper-splitter places the overlay before cropping.
Looking at the help:
usage: wallpaper-splitter.py [-h] --monitor <monitor_def_file.json> [--quiet]
[--verbose]
[--left | --right | --left-padding LEFT_PADDING | --right-padding RIGHT_PADDING]
[--top | --bottom | --top-padding TOP_PADDING | --bottom-padding BOTTOM_PADDING]
[--crop_only]
img_file [img_file ...]
Wallpaper-Splitter
positional arguments:
img_file Image files to convert
optional arguments:
-h, --help show this help message and exit
--monitor <monitor_def_file.json>, -m <monitor_def_file.json>
Monitor Layout Definition JSON File
--quiet, -q Quiet Output
--verbose, -v Verbose Output
Crop Padding:
--left Left justify the cropped images
--right Right justify the cropped images
--left-padding LEFT_PADDING
Left Padding value
--right-padding RIGHT_PADDING
Right Padding value
--top Top justify the cropped images
--bottom Bottom justify the cropped images
--top-padding TOP_PADDING
Top Padding value
--bottom-padding BOTTOM_PADDING
Bottom Padding value
Step Selection:
--crop_only Do not resize the output images. Crop only
--left, --right, --left-padding, --right-padding, --top, --bottom, --top-padding, and --bottom-padding can be used to slide the layout window.
After you have created a monitor definition file, simply tell wallpaper-splitter to split your images for you:
> python3 src/wallpaper-splitter.py -m resources/monitor_defs/6_monitors.json \
> image.jpg --left-padding 3800
Monitor Layout read from definition file:
+-------------------------+ +
|Top | ^
|1920x1200 | |
| | |
| | |
| | |
| | 2
| | 4
+-------------------------+-------------------------+-------------------------+0
|Left |Middle |Right |0
|1920x1200 |1920x1200 |1920x1200 ||
| | | ||
| | | ||
| | | ||
| | | ||
+-------------------------+-------------------------+-------------------------+V
+<-----------------------------------5760------------------------------------->+
Processing: image.jpg
Projection of monitor definition file onto image.jpg:
+
^
|
|
+-------------------------+ |
|Top | |
|1920x1200 | |
| | |
| | |
| | |
| | 2
| | 5
+-------------------------+-------------------------+-------------------------+6
|Left |Middle |Right |0
|1920x1200 |1920x1200 |1920x1200 ||
| | | ||
| | | ||
| | | ||
| | | ||
| | | ||
+-------------------------+-------------------------+-------------------------+|
|
|
V
+<-----------------------------------4096------------------------------------->+
>
- GUI?
Show layout overlay on image?- Re-implement as a Gimp Plugin?
- Start a collection of Monitor Definition Files?
There is nothing about wallpaper-splitter that makes it specific to wallpapers. It could be used to split feeds from a webcam, etc.
Patches are welcome.
Thanks,
Barry