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https://github.com/daleroberts/tv

Quickly view (satellite) imagery directly in your terminal using Unicode 9.0 characters and true color.
https://github.com/daleroberts/tv

command-line image python true-color unicode unicode-characters visualization

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Quickly view (satellite) imagery directly in your terminal using Unicode 9.0 characters and true color.

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README 

        

**tv** ("textview") is a small tool to quickly view high-resolution multi-band imagery directly in your terminal. It was designed for working with (very large) satellite imagery data over a low-bandwidth connection. For example, you can directly visualise a Himawari 8 (11K x 11K pixel) image of the Earth directly from its URL:






It is built upon the wonderful [GDAL](http://www.gdal.org) library so it is able to load a large variety of image formats (GeoTiff, PNG, Jpeg, NetCDF, ...) and subsample the image as it reads from disk so it can handle very large files quickly. It has the ability to read filenames (or URLs) from `stdin` and load files directly from URLs without writing locally to disk. Command line options are styled after `gdal_translate` such as:



  *  `-b` to specify the bands (and ordering) to use,

  * `-srcwin xoff yoff xsize ysize` to view a subset of the image,

  * `-r` to specify the subsampling algorithm (`nearest`, `bilinear`, `cubic`, `cubicspline`, `lanczos`, `average`, `mode`).



**tv** is completely implemented in Python 3 using only Numpy and GDAL 2.0.



My rendering approach is different from other tools such as [hiptext](https://github.com/jart/hiptext) as I use:



 * [Unicode 9.0 block characters](https://en.wikipedia.org/wiki/Block_Elements)

 * [True color terminal support](https://gist.github.com/XVilka/8346728)



This means that you get **amazingly better results** as long as your terminal and font supports it. Here is a comparison between **hiptext** (left) and **tv** (right) using their [benchmark image](https://github.com/jart/hiptext/blob/master/obama.jpg) of Barack Obama using the standard MacOS font 'Menlo Regular' at size 11 in [iTerm 2.0](https://www.iterm2.com/index.html).








You can easily zoom in to get better detail or make the output smaller.






You can quickly view very large files over low-bandwidth connections (e.g., mobile). For example, visualising a 46GB single-band 176000 x 140000 pixel image using nearest neighbour subsampling located on the [raijin supercomputer](http://nci.org.au/systems-services/national-facility/peak-system/raijin/).






It can detect URLs on the standard input which allows you to use it in combination with other tools such as [landsat-util](https://github.com/developmentseed/landsat-util) to quickly visualise thumbnails before you perform a full download.






You can directly give a URL on the command line.






If you have a image with more than 3 bands (channels), you can specify the ordering and the bands that you would like to load into the RGB channels.






You can stack multiple images into the red/green/blue channel or handle multiple subsets of a NetCDF file.






If you really want to throttle back the number of unicode characters used (e.g., if your font or terminal doesn't support many unicode characters), you can do it with a command line option. The following example shows how to use only the block character or a half-height character as well.






Using a GNU parallel, you can do silly things like create a low-fi animation of the Earth viewed from the Himawari-8 satellite.



```

parallel --willcite --tty --header : tv -w 60 -urls http://himawari8-dl.nict.go.jp/himawari8/img/D531106/thumbnail/550/2016/06/{dy}/{hr}{tenmin}000_0_0.png  ::: dy 06 ::: hr 06 ::: tenmin {0..5}

```






## FAQ



### How do I install it?



`tv` is now a Python package so you can install it directly using `pip` if you have GDAL 2.x installed.



To install these dependencies on a Mac with [homebrew](http://brew.sh) do:

```

brew install gdal --with-complete --without-python --HEAD

brew install python3



pip3 install tv

```



On Ubuntu Linux do:

```

sudo apt install python3 libgdal-dev

export CPLUS_INCLUDE_PATH=/usr/include/gdal

export C_INCLUDE_PATH=/usr/include/gdal



pip3 install tv

```



### Does it work on Windows using PuTTY?



Yes if you install a [patched version](https://github.com/halcy/PuTTY) of PuTTY and use the [Deja Vu Mono Book](http://dejavu-fonts.org/wiki/Main_Page) which has support for Unicode 9.0 block characters.



If you **do not** have administrator rights on you Windows machine, you can load the Deja Vu font for your login session using the [regfont](https://github.com/dcpurton/regfont) tool.



### Does it support TMUX?



If you use TMUX, you'll need version >2.2 for true color support. [Here](https://deductivelabs.com/en/2016/03/using-true-color-vim-tmux/) is a description on how to enable true color in TMUX. Personally, I've found that the best way is to place these lines at the end of your `.tmux.conf` file:

```

set -g default-terminal "screen-256color"

set -ga terminal-overrides ",xterm-256color:Tc"

```