section	x-masysma-name	title	date	lang	author	keywords	x-masysma-version	x-masysma-website	x-masysma-repository	x-masysma-owned	x-masysma-copyright
32	image_viewer	Image Viewer Scripts	2020/12/18 22:59:34	en-US	Linux-Fan, Ma_Sys.ma (Ma_Sys.ma@web.de)	mdvl shell script linux python images plan_view	1.0.0	https://masysma.net/32/image_viewer.xhtml	https://www.github.com/m7a/bp-image-viewer	1	Copyright (c) 2020 Ma_Sys.ma. For further info send an e-mail to Ma_Sys.ma@web.de.

Introduction

This repository provides Ma_Sys.ma Image Viewer scripts. These are intended to supplement more heavyweight applications like eog(1) by quick but feature-reduced scripts.

The idea behind these scripts stems from having many scanned-in pages and the need for some specific functions combined with keyboard-driven usage. As a result, the first script plan_view.py is controlled entirely by keyboard and provides predefined zoom-levels (1:1, fit to window and fit to width) useful for viewing scanned pages.

As plan_view.py was found to be slightly incomplete and also slow especially wrt. zooming, an attempt to reconstruct most of the functionality using an existing image viewer feh was made. This is implemented in script ma_plan_view_feh which is the default “image viewer” on MDVL systems (cf. vifmrc from conf-cli(32)).

Ma_Sys.ma Plan View plan_view.py

plan_view.py is invoked taking as argument a single directory which is scanned for image files in a non-recursive manner. Afterwards, the first in list is displayed. Plan View can then be controlled by the following keybindings (copied from the help screen):

Keys Action

---

F1 Display this help F2 Version information F5, CTRL-R Reload current file r Reload directory F10, ESC, q, CTRL-W, ALT-F4 Exit F11 Toggle fullscreen mode Page Down Page down (next file if end of page reached) Page Up Page up (previous file if begin of page reached) Home Go to first file End Go to last file c Center, adjust image to fit page width $ Zoom out until the whole image is visible 0 Restore original image size o, g, d open, goto, change dir: change directory CTRL-[SCROLL] Zoom Space, l, Right Next file. Backspace, h, Left Previous file. p Display current filename. n Note filename to planview_sel.txt e Toggle honor exif information. m Toggle maximized. b Toggle dark background color.

An older version of plan_view.py can also be found on https://pastebin.com/BbRES3Ve.

Notable Features

Notable features include

• The ability to navigate image contents as if it were pages by means of the [Page Up] and [Page Down] keys.
• The zoom to fit window width (key [c])
• Shortcut [n] to save image file name to planview_sel.txt file. This feature is very useful for non-scanned images to select either favorite or to-be-deleted images (depending on user's choice). The contents of planview_sel.txt can be processed manually or by supplementary script mvsel.

OS Information

plan_view.py has only ever been tested on Linux systems. However, given that it is Python and GTK it may as well work on Windows, too.

Script mvsel

A common task when processing image files is to decide for some of the images to be further processed or deleted. To do this interactively, shortuct key [n] in Plan View can be used. Afterwards, script mvsel can process this file as follows:

mvsel dir : Moves all of the selected files to directory dir. mvsel -d : Deletes all of the selected files.

Feh-based Image Viewing

As feh(1) is quite versatile, it seemed that most of plan_view.py's features could be implemented by providing a suitable configuration file. The following Plan View features do not seem to be provided out-of-the box by feh:

• Ability to note file names to planview_sel.txt
• Ability to change directory interactively.

feh can be extend by custom “actions” which allow these features to be added by means of a controlling shell script. As a result, script ma_plan_view_feh was created. It invokes feh and maps two actions to the specific functions described above.

Note, that the shell script itself does not implement Plan View-like keybindings. Instead, it relies on a separate configuration file (from package mdvl-conf-gui) for configuring the keyboard shortcuts.

Also, from plan_view.py to ma_plan_view_feh, the following differences may be observed:

• Default mode is no longer 0, but rather $.
• Switching to different directory does not work as reliable as before. (It is unclear why, but sometimes the feh instance from the previous directory will not close).
• feh acts recursively by default.

Reduced Features

While most image viewing tasks can be solved by means of the scripts provided here, there are some special cases for which programs like eog are better:

• zoom-intensive operations
• printing image files to paper
• animated images (e.g. .gif files)