https://github.com/rahji/greyscale
Command-line tool for interrogating greyscale images
https://github.com/rahji/greyscale
charmbracelet cli command-line-tool golang grayscale grayscale-images images
Last synced: 13 days ago
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Command-line tool for interrogating greyscale images
- Host: GitHub
- URL: https://github.com/rahji/greyscale
- Owner: rahji
- License: mit
- Created: 2024-07-14T16:23:43.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-07-16T04:08:34.000Z (over 1 year ago)
- Last Synced: 2025-03-27T13:39:43.689Z (7 months ago)
- Topics: charmbracelet, cli, command-line-tool, golang, grayscale, grayscale-images, images
- Language: Go
- Homepage:
- Size: 361 KB
- Stars: 4
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ▧▩▤▥▦ greyscale
A command-line tool for interrogating greyscale images.
## Usage
`greyscale` has a few commands and subcommands:
* `greyscale list` lists the 16 grey names that the `show` commands use
* `greyscale show info` shows details about the image specified by the `--infile` flag
* `greyscale show colors` shows a histogram of the greys that make up the `--infile` image
* `greyscale pick` show the grey color (0-255 or HTML hex string) at a given pixel
The `show info` command's output can be filtered using `--dimensions`, `--width`, or `--height`.
This can be useful for piping a single piece of information to another command.
`show colors` has several optional flags:
* `--nonzero` filters out any greys that have 0% representation in the image
* `--csv` skips the fancy table rendering and outputs comma-separated values
* `--top n` only shows the histogram lines for the *n* most frequent greys in the image
* `--pixels x,y:n` filters the input to only include pixels starting at `x,y` and including `n` pixels only. If the value of `n` would extend the scope beyond the end of the image, it will include pixels from `x,y` to the end of the image.
## Sample Images
There are a number of sample images in the `samples` folder. The best image to test with is `8bitgreyscale.png`. Some images are included to show how other colorspaces are displayed by `greyscale show info`.
Worthy of note is the difference between `8bitgreyscale.png` and `32bitgreyscale.png`. Both files look the same visually, but the latter has some slight variation in the grey squares, which is visible in the histogram shown by `greyscale show colors`
## Installation
The easiest way to install is to download the appropriate archive file from the [Releases](https://github.com/rahji/greyscale/releases/latest) page, place the `greyscale` binary [somewhere in your path](https://zwbetz.com/how-to-add-a-binary-to-your-path-on-macos-linux-windows/), and run it from your terminal (eg: Terminal.app in MacOS or [Windows Terminal](https://apps.microsoft.com/store/detail/windows-terminal/9N0DX20HK701?hl=en-us&gl=us&rtc=1))
**OR** If you have `go` installed you can clone this repo and run `mkdir -p ./bin && make build`
**OR** If you want to use `go install` instead, you can run the following command while making sure to use the [latest version number](https://github.com/rahji/greyscale/tags):
```bash
go install -ldflags="-X 'github.com/rahji/greyscale/cmd.version=1.0.1'" github.com/rahji/greyscale@latest
```
## Notes
It's important to realize that `greyscale` *assumes* your image is actually
greyscale. You can run it against a color image. It just won't produce useful
results.