vain · October 5, 2010 18:59 · Apr 22, 2011 · Oct 5, 2010 · Oct 5, 2010 · Oct 5, 2010
diff --git a/gistfile1.sh b/gistfile1.sh
@@ -9,7 +9,7 @@ colors="$(tput colors)"
 size="$(($(tput cols) - 2))x$(($(tput lines) - 2))"
 
 # Process arguments.
-while getopts nc:s: name
+while getopts nc:s:b: name
 do
 	case $name in
 		n)
@@ -24,6 +24,10 @@ do
 			# Desired size?
 			size="$OPTARG"
 			;;
+		b)
+			# Background for transparent images?
+			transparentbg=(-background "$OPTARG")
+			;;
 	esac
 done
 shift $((OPTIND - 1))
@@ -55,6 +59,7 @@ do
 	# Convert the image into a PPM image which can easily be read by
 	# awk.
 	convert \
+		"${transparentbg[@]}" \
 		-compress none \
 		-depth 8 \
 		-resize "$size" \

diff --git a/gistfile1.sh b/gistfile1.sh
@@ -130,9 +130,9 @@ do
 					# and full black are not part of the ramp.
 					g = $i
 					if (g == 255)
-						printf "%s%s%s", white, blank, reset
+						printf "\033[48;5;231m%s%s", blank, reset
 					else if (g == 0)
-						printf "%s%s%s", black, blank, reset
+						printf "\033[48;5;16m%s%s", blank, reset
 					else
 					{
 						printf "\033[48;5;%dm%s%s",

diff --git a/gistfile1.sh b/gistfile1.sh
@@ -57,7 +57,6 @@ do
 	convert \
 		-compress none \
 		-depth 8 \
-		-filter box \
 		-resize "$size" \
 		"${squash[@]}" \
 		"$1" "ppm:-" |
@@ -122,8 +121,31 @@ do
 			}
 			else
 			{
-				printf "\033[48;5;%dm%s%s",
-					(16 + r * 36 + g * 6 + b), blank, reset
+				if (r == g && g == b)
+				{
+					# Try to use the full grayscale ramp. Using "r", "g"
+					# and "b" automatically uses some fuzziness because
+					# theyve already been divided by 51. But now, we
+					# reset "g" to the real grayscale value. Full white
+					# and full black are not part of the ramp.
+					g = $i
+					if (g == 255)
+						printf "%s%s%s", white, blank, reset
+					else if (g == 0)
+						printf "%s%s%s", black, blank, reset
+					else
+					{
+						printf "\033[48;5;%dm%s%s",
+							(int(($i / 255) * 24) + 232), blank, reset
+					}
+				}
+				else
+				{
+					# Find the nearest neighbor in XTerms 6x6x6 color
+					# cube.
+					printf "\033[48;5;%dm%s%s",
+						(16 + r * 36 + g * 6 + b), blank, reset
+				}
 			}
 
 			pixel++

diff --git a/gistfile1.sh b/gistfile1.sh
@@ -52,6 +52,8 @@ fi
 # Remaining arguments are filenames.
 while (( $# > 0 ))
 do
+	# Convert the image into a PPM image which can easily be read by
+	# awk.
 	convert \
 		-compress none \
 		-depth 8 \
@@ -82,7 +84,8 @@ do
 		# image width.
 		while (i < 3)
 		{
-			getline
+			if (getline <= 0)
+				break
 			if (!($0 ~ /^#/ || $0 == ""))
 				i++
 			if (i == 2)

diff --git a/gistfile1.sh b/gistfile1.sh
@@ -4,7 +4,7 @@
 # https://bbs.archlinux.org/viewtopic.php?id=106089
 
 # Defaults.
-doublespace="yes"
+doublexres="yes"
 colors="$(tput colors)"
 size="$(($(tput cols) - 2))x$(($(tput lines) - 2))"
 
@@ -13,8 +13,8 @@ while getopts nc:s: name
 do
 	case $name in
 		n)
-			# Use two spaces instead of one space for each pixel?
-			doublespace="no"
+			# Don't double the resolution in X direction?
+			doublexres="no"
 			;;
 		c)
 			# Number of colors?
@@ -34,18 +34,20 @@ then
 	exit 1
 fi
 
-# When using two spaces for each pixel, we have to divide the available
-# width by 2.
-wid="${size%x*}"
-hei="${size#*x}"
-if [[ "$doublespace" == "yes" ]]
+if [[ "$doublexres" == "yes" ]]
 then
-	space="  "
-	wid=$((wid / 2))
+	# First, we assume that there's twice as much space in Y direction.
+	wid="${size%x*}"
+	hei="${size#*x}"
+	hei=$((hei * 2))
+	size="${wid}x${hei}"
+
+	# Afterwards, squash the image. This results in twice the pixels in
+	# X direction.
+	squash=(-scale "100%x50%")
 else
-	space=" "
+	squash=()
 fi
-size="${wid}x${hei}"
 
 # Remaining arguments are filenames.
 while (( $# > 0 ))
@@ -55,11 +57,12 @@ do
 		-depth 8 \
 		-filter box \
 		-resize "$size" \
+		"${squash[@]}" \
 		"$1" "ppm:-" |
 		gawk '
 	BEGIN {
 		# Define colors and width of one pixel.
-		blank = "'"$space"'"
+		blank = " "
 		reset = "'"$(tput sgr0)"'"
 		black = "'"$(tput setab 0)"'"
 		blue = "'"$(tput setab 4)"'"

diff --git a/gistfile1.sh b/gistfile1.sh
@@ -0,0 +1,138 @@
+#!/bin/bash
+
+# Based on the "Shell image viewer" by Andreas Schönfelder:
+# https://bbs.archlinux.org/viewtopic.php?id=106089
+
+# Defaults.
+doublespace="yes"
+colors="$(tput colors)"
+size="$(($(tput cols) - 2))x$(($(tput lines) - 2))"
+
+# Process arguments.
+while getopts nc:s: name
+do
+	case $name in
+		n)
+			# Use two spaces instead of one space for each pixel?
+			doublespace="no"
+			;;
+		c)
+			# Number of colors?
+			colors="$OPTARG";
+			;;
+		s)
+			# Desired size?
+			size="$OPTARG"
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+if [[ "$colors" != 8 ]] && [[ "$colors" != 256 ]]
+then
+	echo "'$colors' colors not supported." >&2
+	exit 1
+fi
+
+# When using two spaces for each pixel, we have to divide the available
+# width by 2.
+wid="${size%x*}"
+hei="${size#*x}"
+if [[ "$doublespace" == "yes" ]]
+then
+	space="  "
+	wid=$((wid / 2))
+else
+	space=" "
+fi
+size="${wid}x${hei}"
+
+# Remaining arguments are filenames.
+while (( $# > 0 ))
+do
+	convert \
+		-compress none \
+		-depth 8 \
+		-filter box \
+		-resize "$size" \
+		"$1" "ppm:-" |
+		gawk '
+	BEGIN {
+		# Define colors and width of one pixel.
+		blank = "'"$space"'"
+		reset = "'"$(tput sgr0)"'"
+		black = "'"$(tput setab 0)"'"
+		blue = "'"$(tput setab 4)"'"
+		green = "'"$(tput setab 2)"'"
+		cyan = "'"$(tput setab 6)"'"
+		red = "'"$(tput setab 1)"'"
+		magenta = "'"$(tput setab 5)"'"
+		yellow = "'"$(tput setab 3)"'"
+		white = "'"$(tput setab 7)"'"
+
+		if ('"$colors"' == 8)
+			divideby = 128
+		else
+			divideby = 51
+
+		# Read first three non-comment and non-empty lines and get the
+		# image width.
+		while (i < 3)
+		{
+			getline
+			if (!($0 ~ /^#/ || $0 == ""))
+				i++
+			if (i == 2)
+				wid = $1
+		}
+	}
+
+	# Read the rest of the image.
+	{
+		for (i = 1; i <= NF; i += 3)
+		{
+			r = int($i / divideby)
+			g = int($(i + 1) / divideby)
+			b = int($(i + 2) / divideby)
+
+			if ('"$colors"' == 8)
+			{
+				if (r == 0 && g == 0 && b == 0)
+					printf "%s%s%s", black, blank, reset
+				if (r == 0 && g == 0 && b == 1)
+					printf "%s%s%s", blue, blank, reset
+				if (r == 0 && g == 1 && b == 0)
+					printf "%s%s%s", green, blank, reset
+				if (r == 0 && g == 1 && b == 1)
+					printf "%s%s%s", cyan, blank, reset
+				if (r == 1 && g == 0 && b == 0)
+					printf "%s%s%s", red, blank, reset
+				if (r == 1 && g == 0 && b == 1)
+					printf "%s%s%s", magenta, blank, reset
+				if (r == 1 && g == 1 && b == 0)
+					printf "%s%s%s", yellow, blank, reset
+				if (r == 1 && g == 1 && b == 1)
+					printf "%s%s%s", white, blank, reset
+			}
+			else
+			{
+				printf "\033[48;5;%dm%s%s",
+					(16 + r * 36 + g * 6 + b), blank, reset
+			}
+
+			pixel++
+			if (pixel == wid)
+			{
+				printf "\n"
+				pixel = 0
+			}
+		}
+	}'
+
+	# One empty line between two images.
+	shift
+	if (( $# > 0 ))
+	then
+		echo
+	fi
+done
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