tv playin around

testdata/tiv.sh

@@ -0,0 +1,62 @@
+#!/bin/bash -e
+
+##  tiv: Image viewer for Linux terminal  ##
+
+# Character dimensions
+# For XTerm (W×H; change with L-Ctrl + RMB):
+#   Huge:       10×20
+#   Large:       9×18
+#   Medium:      8×13
+#   Small:       7×14
+# * Default:     6×13
+#   Tiny:        5×8 (recommended)
+#   Unreadable:  1×2 (high resolution, slowest rendering, without double horizontal resolution)
+char_w=5
+char_h=8
+
+# If file doesn't exist, then die with 'No such file or directory' exit code
+if [ ! -f "$1" ]
+  then exit 2
+  elif grep -q image <<<$(file "$1"); then # If file is image…
+    cols_no=$(($(tput cols)*6))
+    lines_no=$(tput lines)
+    window_w=$((cols_no*char_w))
+    window_h=$((lines_no*char_h))
+    img_dims=$(identify -format '%w %h' "$1")
+    img_w=$(awk '{print $1}' <<<$img_dims)
+    img_h=$(awk '{print $2}' <<<$img_dims)
+    char_asp_r="($char_w/$char_h)"
+
+# Zoom parameter; you can use decimal comma
+    case "$2" in
+      "") zoom=100;;
+       *) zoom=$(sed -e 's/,/./' <<<$2);;
+    esac
+
+# Determine whether the image is landscape or portrait (or square) to ensure the image adapts to window/screen
+    if [ $((img_w*window_h)) -gt $((img_h*window_w/6)) ]
+      then out_v=$(bc -l <<<"scale=6; $cols_no/$img_w*$zoom*$char_asp_r/6")
+      else out_v=$(bc -l <<<"scale=6; $lines_no/$img_h*$zoom")
+    fi
+
+# MAIN ENGINE
+# printf "\e[;f" = move cursor to top left corner and further:
+# * Remove comment (if any)
+# * Use first frame from animated image (eg GIF)
+# * Convert to 8-bit depth
+# * Use Lanczos' (sharp but without distortions) interpolation filter, resize image to fit to the window
+# * Center image, fill empty spaces with black
+# * Export to ASCII PPM image file format and send to pipe, where:
+#    * Remove the PPM header
+#    * Align output to $cols_no columns (window width*6 [R G B r g b - FOREGROUND/background])
+#    * Convert 'R G B r g b' decimal values to ANSI escape code for set foreground/background color of the '▌' character
+# … and print formatted output to STDOUT (or file)
+# Reset formatting and move cursor to the top left corner
+    printf "\e[;f$(convert -comment "" "$1"[0] -depth 8 -filter Lanczos2 -resize $(bc -l <<<"scale=6; $out_v/$char_asp_r*2")%x${out_v}\
+    -background black -gravity center -extent $((cols_no/3))x${lines_no}$3 -compress none ppm:- |\
+    tail -n+5 | xargs -n $cols_no |\
+    sed -e 's:$: :g;s:\([0-9]\+\) \([0-9]\+\) \([0-9]\+\) \([0-9]\+\) \([0-9]\+\) \([0-9]\+\) :\\e\[38;2;\1;\2;\3;48;2;\4;\5;\6m▌:g')\e[m\e[;f"
+
+# If file is not an image, then exit with 'Wrong medium type' exit code
+    else exit 124
+fi