version 1.2

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Aaron Liu 2023-09-29 21:06:50 -04:00
parent aa634424d6
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13
.gitignore vendored
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@ -69,6 +69,18 @@ hs_err_pid*
.directory
###Visual Studio###
.vs/
*.pdb
*.idb
*.ilk
x64/
*.sln
*.vcxproj
*.vcxproj.*
###OSX###
.DS_Store
@ -78,7 +90,6 @@ hs_err_pid*
# Icon must end with two \r
Icon
# Thumbnails
._*

209
LICENSE
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@ -1,201 +1,14 @@
Apache License
Version 2.0, January 2004
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Copyright (c) 2023 Stefan Haustein and Aaron Liu
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@ -2,36 +2,48 @@
Small C++ program to display images in a (modern) terminal using RGB ANSI codes and unicode block graphic characters.
There are various similar tools (such as `timg`) using the unicode half block character to display two 24bit pixels per character cell. This program enhances the resolution by mapping 4x8 pixel cells to different unicode characters, using the following algorithm:
For each 4x8 pixel cell of the (potentially downscaled) image:
There are various similar tools (such as `timg`) that use the unicode half block character to display two 24bit pixels per character cell. This program enhances the resolution by mapping 4x8 pixel cells to different unicode characters, using the following algorithm for each 4x8 pixel cell of the (potentially downscaled) image:
1. Find the color channel (R, G or B) that has the biggest range of values for the current cell
2. Split this range in the middle and create a corresponding bitmap for the cell
4. Compare the bitmap to the assumed bitmaps for various unicode block graphics characters
5. Re-calculate the foreground and background colors for the chosen character.
3. Compare the bitmap to the assumed bitmaps for various unicode block graphics characters
4. Re-calculate the foreground and background colors for the chosen character.
See the difference by disabling this optimization using the `-0` option. Or just take a look at the comparison image at the end of this text.
## Usage
```sh
tiv [options] <filename> [<filename>...]
```
The shell will expand wildcards. By default, thumbnails and file names will be displayed if more than one image is provided. For a list of options, run the command without any parameters or with `--help`.
## News
- 2019-03-26: Exciting week: @Cableo has fixed output redirection, @boretom has added cross-compilation support to the build file and @AlanDeSmet has fixed tall thumbnails and greyscale images.
- 2019-01-14: Install via snap: `sudo snap install --edge tiv`
- 2020-04-09: @aaronliu0130 has added homebrew support.
- 2020-07-05: @cxwx has fixed homebrew support.
- 2021-05-21: @aaronliu0130 has added Apple Clang support.
- 2022-02-02: @aaronliu0130 added homebrew support from homebrew-core.
- 2020-10-22: The Java version is now **deprecated**. Development has long shifted to the C++ version since that was created, and the last meaningful update to it was in 2016.
- 2021-05-22: We now support Apple Clang, thanks to the C++ filesystem library being no longer experimental. Issue forms have also been added to the GitHub repository.
- 2023-09-29: Today marks the 40th anniversary of the GNU project. If you haven't learned the news concerning it and Stallman, please do. In project news, @aaronliu0130 will probably be developing this project from now on as the original author is inactive. Support for MSVC has been added and the repository is now under an Apache 2.0 or GPL3 dual license. CI building for each release will hopefully be setup soon. The main program has also adopted a mostly Google code-style because I (aaron) think it simply makes sense.
`SPDX-License-Identifier: Apache-2.0 OR GPL-3.0-or-later`
## Installation
> [!IMPORTANT]
> All installation methods require installing ImageMagick, a required dependency. Most package managers should install it automatically.
### Build from source
Our makefile currently only supports `g++`. It should be possible to compile `tiv` manually using any of your favorite compilers that support C++20 and Unix headers (`ioctl.h`, specifically) or `windows.h`. PRs are welcome.
```sh
brew install imagemagick || yum install ImageMagick || sudo apt install imagemagick
git clone https://github.com/stefanhaustein/TerminalImageViewer.git
cd TerminalImageViewer/src/main/cpp
cd TerminalImageViewer/src
make
# To move the tiv binary into your PATH (hopefully), also do
sudo make install
```
### Homebrew
Option 1:
@ -51,27 +63,25 @@ brew install terminalimageviewer
sudo snap install --edge tiv
## Usage
## Packages
tiv [options] <filename(s)>
- @aaronliu0130 has added homebrew support.
- @megamaced has created [an RPM for SUSE](https://build.opensuse.org/package/show/home:megamaced/terminalimageviewer)
- @bperel has created [a Docker image](https://hub.docker.com/r/bperel/terminalimageviewer)
- @teresaejunior has created a snapcraft.yaml file, which can build a Snap package with `sudo docker run -it --rm -v "$PWD:$PWD" -w "$PWD" snapcore/snapcraft sh -c 'apt-get update && snapcraft'`, and then installed with `sudo snap install --dangerous ./*.snap`. This is no longer supported.
- An AUR package is also available, though the maintainer appears to be inactive. Replacements coming soon.
The shell will expand wildcards. By default, thumbnails and file names will be displayed if more than one image is provided. To display a list of options, just run the command without any parameters.
## Contributions
## Packages / Contributions
- megamaced has created a RPM for SUSE:
<https://build.opensuse.org/package/show/home:megamaced/terminalimageviewer>
- bperel has created a Docker image:
<https://hub.docker.com/r/bperel/terminalimageviewer>
- teresaejunior has created a snapcraft.yaml file, which can build a Snap package with `sudo docker run -it --rm -v "$PWD:$PWD" -w "$PWD" snapcore/snapcraft sh -c 'apt-get update && snapcraft'`, and then installed with `sudo snap install --dangerous ./*.snap`.
- aaronliu0130 has added brew support.
- 2019-03-26: Exciting week: @Cableo has fixed output redirection, @boretom has added cross-compilation support to the build file and @AlanDeSmet has fixed tall thumbnails and greyscale images.
- 2020-07-05: @cxwx has fixed homebrew support.
I am happy to accept useful contributions under the Apache 2.0 licencse, but...
- Before investing in larger contributions, please use an issue to discuss this
- Pull requests should be as "atomic" as possible. I won't accept any pull request doing multiple things at once.
- This library currently only depends on ImageMagic as an image processing library and I'd prefer to keep it that way.
- Support for additional platforms, CPUs or similar will require somebody who is happy to help with maintenance, in particular, if I don't have access to it.
- This program currently only depends on CImg and ImageMagick as image processing libraries and I'd prefer to keep it that way.
- Support for additional platforms, CPUs or similar will require somebody who is happy to help with maintenance, in particular if I don't have access to it.
## Common problems
@ -82,14 +92,14 @@ I am happy to accept useful contributions under the Apache 2.0 licencse, but...
## Examples
Most examples were shot with the Java version of this program, which should have equivalent output but slower by millenia in CPU years.
![Examples](https://i.imgur.com/yWRZ3yk.png)
If multiple images match the filename spec, thumbnails are shown.
![Thumbnails](https://i.imgur.com/PTYgSqz.png)
## Comparison to Using Half-Block Characters Only
The top image was generated with the character optimization disabled via the `-0` option.
For the example below, the top image was generated with the character optimization disabled via the `-0` option.
![Comparison](https://i.imgur.com/OzdCeh6.png)

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@ -12,7 +12,7 @@ prefix ?= /usr/local
exec_prefix ?= $(prefix)
bindir ?= $(exec_prefix)/bin
override CXXFLAGS += -std=c++17 -Wall -fexceptions
override CXXFLAGS += -std=c++20 -Wall -fexceptions
override LDFLAGS += -pthread
all: $(PROGNAME)

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@ -34,7 +34,7 @@ public class TerminalImageViewer {
" - Use -w and -h to set the maximum width and height in characters (defaults: 80, 24).\n" +
" - Use -256 for 256 color mode, -grayscale for grayscale and -stdin to obtain file names from stdin.\n" +
" - When multiple files are supplied, -c sets the number of images per row (default: 4)." +
"NOTE: This version of TerminalImageViewer is not regularly updated. Please use the C++ version instead.\n");
"NOTE: This version of TerminalImageViewer is deprecated. Please use the C++ version instead.\n");
return;
}

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@ -1,648 +0,0 @@
#include <iostream>
#include <bitset>
#include <cmath>
#include <fstream>
#include <map>
#include <string>
#include <vector>
#include <array>
#include <sys/ioctl.h>
#include <filesystem>
#define cimg_display 0
#include "CImg.h"
//using namespace std;
const int FLAG_FG = 1;
const int FLAG_BG = 2;
const int FLAG_MODE_256 = 4;
const int FLAG_24BIT = 8;
const int FLAG_NOOPT = 16;
const int FLAG_TELETEXT = 32;
const int COLOR_STEP_COUNT = 6;
const int COLOR_STEPS[COLOR_STEP_COUNT] = {0, 0x5f, 0x87, 0xaf, 0xd7, 0xff};
const int GRAYSCALE_STEP_COUNT = 24;
const int GRAYSCALE_STEPS[GRAYSCALE_STEP_COUNT] = {
0x08, 0x12, 0x1c, 0x26, 0x30, 0x3a, 0x44, 0x4e, 0x58, 0x62, 0x6c, 0x76,
0x80, 0x8a, 0x94, 0x9e, 0xa8, 0xb2, 0xbc, 0xc6, 0xd0, 0xda, 0xe4, 0xee};
const unsigned int BITMAPS[] = {
0x00000000, 0x00a0,
// Block graphics
// 0xffff0000, 0x2580, // upper 1/2; redundant with inverse lower 1/2
0x0000000f, 0x2581, // lower 1/8
0x000000ff, 0x2582, // lower 1/4
0x00000fff, 0x2583,
0x0000ffff, 0x2584, // lower 1/2
0x000fffff, 0x2585,
0x00ffffff, 0x2586, // lower 3/4
0x0fffffff, 0x2587,
//0xffffffff, 0x2588, // full; redundant with inverse space
0xeeeeeeee, 0x258a, // left 3/4
0xcccccccc, 0x258c, // left 1/2
0x88888888, 0x258e, // left 1/4
0x0000cccc, 0x2596, // quadrant lower left
0x00003333, 0x2597, // quadrant lower right
0xcccc0000, 0x2598, // quadrant upper left
//0xccccffff, 0x2599, // 3/4 redundant with inverse 1/4
0xcccc3333, 0x259a, // diagonal 1/2
//0xffffcccc, 0x259b, // 3/4 redundant
//0xffff3333, 0x259c, // 3/4 redundant
0x33330000, 0x259d, // quadrant upper right
//0x3333cccc, 0x259e, // 3/4 redundant
//0x3333ffff, 0x259f, // 3/4 redundant
// Line drawing subset: no double lines, no complex light lines
0x000ff000, 0x2501, // Heavy horizontal
0x66666666, 0x2503, // Heavy vertical
0x00077666, 0x250f, // Heavy down and right
0x000ee666, 0x2513, // Heavy down and left
0x66677000, 0x2517, // Heavy up and right
0x666ee000, 0x251b, // Heavy up and left
0x66677666, 0x2523, // Heavy vertical and right
0x666ee666, 0x252b, // Heavy vertical and left
0x000ff666, 0x2533, // Heavy down and horizontal
0x666ff000, 0x253b, // Heavy up and horizontal
0x666ff666, 0x254b, // Heavy cross
0x000cc000, 0x2578, // Bold horizontal left
0x00066000, 0x2579, // Bold horizontal up
0x00033000, 0x257a, // Bold horizontal right
0x00066000, 0x257b, // Bold horizontal down
0x06600660, 0x254f, // Heavy double dash vertical
0x000f0000, 0x2500, // Light horizontal
0x0000f000, 0x2500, //
0x44444444, 0x2502, // Light vertical
0x22222222, 0x2502,
0x000e0000, 0x2574, // light left
0x0000e000, 0x2574, // light left
0x44440000, 0x2575, // light up
0x22220000, 0x2575, // light up
0x00030000, 0x2576, // light right
0x00003000, 0x2576, // light right
0x00004444, 0x2577, // light down
0x00002222, 0x2577, // light down
// Misc technical
0x44444444, 0x23a2, // [ extension
0x22222222, 0x23a5, // ] extension
0x0f000000, 0x23ba, // Horizontal scanline 1
0x00f00000, 0x23bb, // Horizontal scanline 3
0x00000f00, 0x23bc, // Horizontal scanline 7
0x000000f0, 0x23bd, // Horizontal scanline 9
// Geometrical shapes. Tricky because some of them are too wide.
//0x00ffff00, 0x25fe, // Black medium small square
0x00066000, 0x25aa, // Black small square
//0x11224488, 0x2571, // diagonals
//0x88442211, 0x2572,
//0x99666699, 0x2573,
//0x000137f0, 0x25e2, // Triangles
//0x0008cef0, 0x25e3,
//0x000fec80, 0x25e4,
//0x000f7310, 0x25e5,
0, 0, // End marker for "regular" characters
// Teletext / legacy graphics 3x2 block character codes.
// Using a 3-2-3 pattern consistently, perhaps we should create automatic variations....
0xccc00000, 0xfb00,
0x33300000, 0xfb01,
0xfff00000, 0xfb02,
0x000cc000, 0xfb03,
0xccccc000, 0xfb04,
0x333cc000, 0xfb05,
0xfffcc000, 0xfb06,
0x00033000, 0xfb07,
0xccc33000, 0xfb08,
0x33333000, 0xfb09,
0xfff33000, 0xfb0a,
0x000ff000, 0xfb0b,
0xcccff000, 0xfb0c,
0x333ff000, 0xfb0d,
0xfffff000, 0xfb0e,
0x00000ccc, 0xfb0f,
0xccc00ccc, 0xfb10,
0x33300ccc, 0xfb11,
0xfff00ccc, 0xfb12,
0x000ccccc, 0xfb13,
0x333ccccc, 0xfb14,
0xfffccccc, 0xfb15,
0x00033ccc, 0xfb16,
0xccc33ccc, 0xfb17,
0x33333ccc, 0xfb18,
0xfff33ccc, 0xfb19,
0x000ffccc, 0xfb1a,
0xcccffccc, 0xfb1b,
0x333ffccc, 0xfb1c,
0xfffffccc, 0xfb1d,
0x00000333, 0xfb1e,
0xccc00333, 0xfb1f,
0x33300333, 0x1b20,
0xfff00333, 0x1b21,
0x000cc333, 0x1b22,
0xccccc333, 0x1b23,
0x333cc333, 0x1b24,
0xfffcc333, 0x1b25,
0x00033333, 0x1b26,
0xccc33333, 0x1b27,
0xfff33333, 0x1b28,
0x000ff333, 0x1b29,
0xcccff333, 0x1b2a,
0x333ff333, 0x1b2b,
0xfffff333, 0x1b2c,
0x00000fff, 0x1b2d,
0xccc00fff, 0x1b2e,
0x33300fff, 0x1b2f,
0xfff00fff, 0x1b30,
0x000ccfff, 0x1b31,
0xcccccfff, 0x1b32,
0x333ccfff, 0x1b33,
0xfffccfff, 0x1b34,
0x00033fff, 0x1b35,
0xccc33fff, 0x1b36,
0x33333fff, 0x1b37,
0xfff33fff, 0x1b38,
0x000fffff, 0x1b39,
0xcccfffff, 0x1b3a,
0x333fffff, 0x1b3b,
0, 1 // End marker for extended TELETEXT mode.
};
struct CharData {
std::array<int, 3> fgColor = std::array<int, 3>{0, 0, 0};
std::array<int, 3> bgColor = std::array<int, 3>{0, 0, 0};
int codePoint;
};
// Return a CharData struct with the given code point and corresponding averag fg and bg colors.
CharData createCharData(const cimg_library::CImg<unsigned char> & image, int x0, int y0, int codepoint, int pattern) {
CharData result;
result.codePoint = codepoint;
int fg_count = 0;
int bg_count = 0;
unsigned int mask = 0x80000000;
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
int* avg;
if (pattern & mask) {
avg = result.fgColor.data();
fg_count++;
} else {
avg = result.bgColor.data();
bg_count++;
}
for (int i = 0; i < 3; i++) {
avg[i] += image(x0 + x, y0 + y, 0, i);
}
mask = mask >> 1;
}
}
// Calculate the average color value for each bucket
for (int i = 0; i < 3; i++) {
if (bg_count != 0) {
result.bgColor[i] /= bg_count;
}
if (fg_count != 0) {
result.fgColor[i] /= fg_count;
}
}
return result;
}
// Find the best character and colors for a 4x8 part of the image at the given position
CharData findCharData(const cimg_library::CImg<unsigned char> & image, int x0, int y0, int flags) {
int min[3] = {255, 255, 255};
int max[3] = {0};
std::map<long,int> count_per_color;
// Determine the minimum and maximum value for each color channel
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
long color = 0;
for (int i = 0; i < 3; i++) {
int d = image(x0 + x, y0 + y, 0, i);
min[i] = std::min(min[i], d);
max[i] = std::max(max[i], d);
color = (color << 8) | d;
}
count_per_color[color]++;
}
}
std::multimap<int,long> color_per_count;
for (auto i = count_per_color.begin(); i != count_per_color.end(); ++i) {
color_per_count.insert(std::pair<int,long>(i->second, i->first));
}
auto iter = color_per_count.rbegin();
int count2 = iter->first;
long max_count_color_1 = iter->second;
long max_count_color_2 = max_count_color_1;
if ((++iter) != color_per_count.rend()) {
count2 += iter->first;
max_count_color_2 = iter->second;
}
unsigned int bits = 0;
bool direct = count2 > (8*4) / 2;
if (direct) {
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
bits = bits << 1;
int d1 = 0;
int d2 = 0;
for (int i = 0; i < 3; i++) {
int shift = 16 - 8 * i;
int c1 = (max_count_color_1 >> shift) & 255;
int c2 = (max_count_color_2 >> shift) & 255;
int c = image(x0 + x, y0 + y, 0, i);
d1 += (c1-c) * (c1-c);
d2 += (c2-c) * (c2-c);
}
if (d1 > d2) {
bits |= 1;
}
}
}
} else {
// Determine the color channel with the greatest range.
int splitIndex = 0;
int bestSplit = 0;
for (int i = 0; i < 3; i++) {
if (max[i] - min[i] > bestSplit) {
bestSplit = max[i] - min[i];
splitIndex = i;
}
}
// We just split at the middle of the interval instead of computing the median.
int splitValue = min[splitIndex] + bestSplit / 2;
// Compute a bitmap using the given split and sum the color values for both buckets.
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
bits = bits << 1;
if (image(x0 + x, y0 + y, 0, splitIndex) > splitValue) {
bits |= 1;
}
}
}
}
// Find the best bitmap match by counting the bits that don't match,
// including the inverted bitmaps.
int best_diff = 8;
unsigned int best_pattern = 0x0000ffff;
int codepoint = 0x2584;
bool inverted = false;
unsigned int end_marker = flags & FLAG_TELETEXT ? 1 : 0;
for (int i = 0; BITMAPS[i + 1] != end_marker; i += 2) {
// Skip all end markers
if (BITMAPS[i + 1] < 32) {
continue;
}
unsigned int pattern = BITMAPS[i];
for (int j = 0; j < 2; j++) {
int diff = (std::bitset<32>(pattern ^ bits)).count();
if (diff < best_diff) {
best_pattern = BITMAPS[i]; // pattern might be inverted.
codepoint = BITMAPS[i + 1];
best_diff = diff;
inverted = best_pattern != pattern;
}
pattern = ~pattern;
}
}
if (direct) {
CharData result;
if (inverted) {
long tmp = max_count_color_1;
max_count_color_1 = max_count_color_2;
max_count_color_2 = tmp;
}
for (int i = 0; i < 3; i++) {
int shift = 16 - 8 * i;
result.fgColor[i] = (max_count_color_2 >> shift) & 255;
result.bgColor[i] = (max_count_color_1 >> shift) & 255;
result.codePoint = codepoint;
}
return result;
}
return createCharData(image, x0, y0, codepoint, best_pattern);
}
int clamp_byte(int value) {
return value < 0 ? 0 : (value > 255 ? 255 : value);
}
double sqr(double n) {
return n*n;
}
int best_index(int value, const int data[], int count) {
int best_diff = std::abs(data[0] - value);
int result = 0;
for (int i = 1; i < count; i++) {
int diff = std::abs(data[i] - value);
if (diff < best_diff) {
result = i;
best_diff = diff;
}
}
return result;
}
void emit_color(int flags, int r, int g, int b) {
r = clamp_byte(r);
g = clamp_byte(g);
b = clamp_byte(b);
bool bg = (flags & FLAG_BG) != 0;
if ((flags & FLAG_MODE_256) == 0) {
std::cout << (bg ? "\x1b[48;2;" : "\x1b[38;2;") << r << ';' << g << ';' << b << 'm';
return;
}
int ri = best_index(r, COLOR_STEPS, COLOR_STEP_COUNT);
int gi = best_index(g, COLOR_STEPS, COLOR_STEP_COUNT);
int bi = best_index(b, COLOR_STEPS, COLOR_STEP_COUNT);
int rq = COLOR_STEPS[ri];
int gq = COLOR_STEPS[gi];
int bq = COLOR_STEPS[bi];
int gray = static_cast<int>(std::round(r * 0.2989f + g * 0.5870f + b * 0.1140f));
int gri = best_index(gray, GRAYSCALE_STEPS, GRAYSCALE_STEP_COUNT);
int grq = GRAYSCALE_STEPS[gri];
int color_index;
if (0.3 * sqr(rq-r) + 0.59 * sqr(gq-g) + 0.11 * sqr(bq-b) <
0.3 * sqr(grq-r) + 0.59 * sqr(grq-g) + 0.11 * sqr(grq-b)) {
color_index = 16 + 36 * ri + 6 * gi + bi;
} else {
color_index = 232 + gri; // 1..24 -> 232..255
}
std::cout << (bg ? "\x1B[48;5;" : "\u001B[38;5;") << color_index << "m";
}
void emitCodepoint(int codepoint) {
if (codepoint < 128) {
std::cout << (char) codepoint;
} else if (codepoint < 0x7ff) {
std::cout << (char) (0xc0 | (codepoint >> 6));
std::cout << (char) (0x80 | (codepoint & 0x3f));
} else if (codepoint < 0xffff) {
std::cout << (char) (0xe0 | (codepoint >> 12));
std::cout << (char) (0x80 | ((codepoint >> 6) & 0x3f));
std::cout << (char) (0x80 | (codepoint & 0x3f));
} else if (codepoint < 0x10ffff) {
std::cout << (char) (0xf0 | (codepoint >> 18));
std::cout << (char) (0x80 | ((codepoint >> 12) & 0x3f));
std::cout << (char) (0x80 | ((codepoint >> 6) & 0x3f));
std::cout << (char) (0x80 | (codepoint & 0x3f));
} else {
std::cerr << "ERROR";
}
}
void emit_image(const cimg_library::CImg<unsigned char> & image, int flags) {
CharData lastCharData;
for (int y = 0; y <= image.height() - 8; y += 8) {
for (int x = 0; x <= image.width() - 4; x += 4) {
CharData charData = flags & FLAG_NOOPT
? createCharData(image, x, y, 0x2584, 0x0000ffff)
: findCharData(image, x, y, flags);
if (x == 0 || charData.bgColor != lastCharData.bgColor)
emit_color(flags | FLAG_BG, charData.bgColor[0], charData.bgColor[1], charData.bgColor[2]);
if (x == 0 || charData.fgColor != lastCharData.fgColor)
emit_color(flags | FLAG_FG, charData.fgColor[0], charData.fgColor[1], charData.fgColor[2]);
emitCodepoint(charData.codePoint);
lastCharData = charData;
}
std::cout << "\x1b[0m" << std::endl;
}
}
struct size {
size(unsigned int in_width, unsigned int in_height) :
width(in_width), height(in_height) {
}
size(cimg_library::CImg<unsigned int> img) :
width(img.width()), height(img.height()) {
}
unsigned int width;
unsigned int height;
size scaled(double scale) {
return size(width*scale, height*scale);
}
size fitted_within(size container) {
double scale = std::min(container.width / (double) width, container.height / (double) height);
return scaled(scale);
}
};
std::ostream& operator<<(std::ostream& stream, size sz) {
stream << sz.width << "x" << sz.height;
return stream;
}
void emit_usage() {
std::cerr << "Terminal Image Viewer v1.1.1" << std::endl << std::endl;
std::cerr << "usage: tiv [options] <image> [<image>...]" << std::endl << std::endl;
std::cerr << " -0 : No block character adjustment, always use top half block char." << std::endl;
std::cerr << " -256 : Use 256 color mode." << std::endl;
std::cerr << " -c <num> : Number of thumbnail columns in 'dir' mode (3)." << std::endl;
std::cerr << " -d : Force 'dir' mode. Automatially selected for more than one input." << std::endl;
std::cerr << " -f : Force 'full' mode. Automatically selected for one input." << std::endl;
std::cerr << " -help : Display this help text." << std::endl;
std::cerr << " -h <num> : Set the maximum height to <num> lines." << std::endl;
std::cerr << " -w <num> : Set the maximum width to <num> characters." << std::endl;
std::cerr << " -x : Use new Unicode Teletext/legacy charactery (experimental)." << std::endl << std::endl;
}
enum Mode {AUTO, THUMBNAILS, FULL_SIZE};
/* Wrapper around CImg<T>(const char*) to ensure the result has 3 channels as RGB
*/
cimg_library::CImg<unsigned char> load_rgb_CImg(const char * const filename) {
cimg_library::CImg<unsigned char> image(filename);
if(image.spectrum() == 1) {
// Greyscale. Just copy greyscale data to all channels
cimg_library::CImg<unsigned char> rgb_image(image.width(), image.height(), image.depth(), 3);
for(unsigned int chn = 0; chn < 3; chn++) {
rgb_image.draw_image(0, 0, 0,chn, image);
}
return rgb_image;
}
return image;
}
int main(int argc, char* argv[]) {
int maxWidth = 80;
int maxHeight = 24;
bool sizeDetectionSuccessful = true;
struct winsize w;
int ioStatus = ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
// If redirecting STDOUT to one file ( col or row == 0, or the previous ioctl call's failed )
if (ioStatus != 0 || (w.ws_col | w.ws_row) == 0) {
ioStatus = ioctl(STDIN_FILENO, TIOCGWINSZ, &w);
if (ioStatus != 0 || (w.ws_col | w.ws_row) == 0) {
std::cerr << "Warning: failed to determine most reasonable size, defaulting to 80x24" << std::endl;
sizeDetectionSuccessful = false;
}
}
if (sizeDetectionSuccessful)
{
maxWidth = w.ws_col * 4;
maxHeight = w.ws_row * 8;
}
int flags = 0;
Mode mode = AUTO;
int columns = 3;
std::vector<std::string> file_names;
int error = 0;
if (argc <= 1) {
emit_usage();
return 0;
}
for (int i = 1; i < argc; i++) {
std::string arg(argv[i]);
if (arg == "-0") {
flags |= FLAG_NOOPT;
} else if (arg == "-c") {
if (i < argc - 1)
columns = std::stoi(argv[++i]);
} else if (arg == "-d") {
mode = THUMBNAILS;
} else if (arg == "-f") {
mode = FULL_SIZE;
} else if (arg == "-w") {
if (i < argc - 1)
maxWidth = 4 * std::stoi(argv[++i]);
} else if (arg == "-h") {
if (i < argc - 1)
maxHeight = 8 * std::stoi(argv[++i]);
} else if (arg == "-256") {
flags |= FLAG_MODE_256;
} else if (arg == "--help" || arg == "-help") {
emit_usage();
} else if (arg == "-x") {
flags |= FLAG_TELETEXT;
} else if (arg[0] == '-') {
std::cerr << "Unrecognized argument: " << arg << std::endl;
} else {
if (std::filesystem::is_directory(arg)) {
for (auto & p : std::filesystem::directory_iterator(arg)) {
if (std::filesystem::is_regular_file(p.path())) {
file_names.push_back(p.path().string());
}
}
} else {
std::ifstream fin(arg.c_str());
if (fin) {
file_names.push_back(arg);
} else {
std::cerr << "Can't open file (permission?): " << arg << std::endl;
}
}
}
}
if (mode == FULL_SIZE || (mode == AUTO && file_names.size() == 1)) {
for (unsigned int i = 0; i < file_names.size(); i++) {
try {
cimg_library::CImg<unsigned char> image = load_rgb_CImg(file_names[i].c_str());
if (image.width() > maxWidth || image.height() > maxHeight) {
size new_size = size(image).fitted_within(size(maxWidth,maxHeight));
image.resize(new_size.width, new_size.height, -100, -100, 5);
}
emit_image(image, flags);
} catch(cimg_library::CImgIOException & e) {
error = 1;
std::cerr << "File format is not recognized for '" << file_names[i] << "'" << std::endl;
}
}
} else {
// Thumbnail mode
unsigned int index = 0;
int cw = (((maxWidth / 4) - 2 * (columns - 1)) / columns);
int tw = cw * 4;
cimg_library::CImg<unsigned char> image(tw * columns + 2 * 4 * (columns - 1), tw, 1, 3);
size maxThumbSize(tw, tw);
while (index < file_names.size()) {
image.fill(0);
int count = 0;
std::string sb;
while (index < file_names.size() && count < columns) {
std::string name = file_names[index++];
try {
cimg_library::CImg<unsigned char> original = load_rgb_CImg(name.c_str());
auto cut = name.find_last_of("/");
sb += cut == std::string::npos ? name : name.substr(cut + 1);
size newSize = size(original).fitted_within(maxThumbSize);
original.resize(newSize.width, newSize.height, 1, -100, 5);
image.draw_image(count * (tw + 8) + (tw - newSize.width) / 2, (tw - newSize.height) / 2, 0, 0, original);
count++;
unsigned int sl = count * (cw + 2);
sb.resize(sl - 2, ' ');
sb += " ";
} catch (std::exception & e) {
// Probably no image; ignore.
}
}
if (count) emit_image(image, flags);
std::cout << sb << std::endl << std::endl;
}
}
return error;
}

720
src/tiv.cpp Normal file
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@ -0,0 +1,720 @@
/*
* Copyright (c) 2023 Aaron Liu
*
* This file is free software: you may copy, redistribute and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* This file is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright (c) 20172021, Stefan Haustein
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <array>
#include <bitset>
#include <cmath>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <map>
#include <string>
#include <vector>
// CImg, the superior grafiks library
#define cimg_display 0
#include "CImg.h"
// First include for detecting console output size,
// everything else for exit codes
#ifdef _POSIX_VERSION
#include <sys/ioctl.h>
#include <sysexits.h>
#endif
#ifdef _WIN32
#include <windows.h>
// Following codes copied from /usr/include/sysexits.h,
// license: https://opensource.org/license/BSD-3-clause/
#define EX_OK 0 /* successful termination */
#define EX__BASE 64 /* base value for error messages */
#define EX_USAGE 64 /* command line usage error */
#define EX_DATAERR 65 /* data format error */
#define EX_NOINPUT 66 /* cannot open input */
#define EX_SOFTWARE 70 /* internal software error */
#define EX_CANTCREAT 73 /* can't create (user) output file */
#define EX_IOERR 74 /* input/output error */
#define EX_TEMPFAIL 75 /* temp failure; user is invited to retry */
#define EX_NOPERM 77 /* permission denied */
#define EX_CONFIG 78 /* configuration error */
#endif
// using namespace std; // haha nope, bad style
// especially when we're also using the CImg namespace
// Implementation of flag representation for flags in the main() method
constexpr int FLAG_FG = 1;
constexpr int FLAG_BG = 2;
constexpr int FLAG_MODE_256 = 4;
constexpr int FLAG_24BIT = 8;
constexpr int FLAG_NOOPT = 16;
constexpr int FLAG_TELETEXT = 32;
// Steps (@TODO: Figure out what exactly they represent)
constexpr int COLOR_STEP_COUNT = 6;
constexpr int COLOR_STEPS[COLOR_STEP_COUNT] = {0, 0x5f, 0x87, 0xaf, 0xd7, 0xff};
constexpr int GRAYSCALE_STEP_COUNT = 24;
constexpr int GRAYSCALE_STEPS[GRAYSCALE_STEP_COUNT] = {
0x08, 0x12, 0x1c, 0x26, 0x30, 0x3a, 0x44, 0x4e, 0x58, 0x62, 0x6c, 0x76,
0x80, 0x8a, 0x94, 0x9e, 0xa8, 0xb2, 0xbc, 0xc6, 0xd0, 0xda, 0xe4, 0xee};
constexpr unsigned int BITMAPS[] = {
0x00000000, 0x00a0,
// Block graphics
// 0xffff0000, 0x2580, // upper 1/2; redundant with inverse lower 1/2
0x0000000f, 0x2581, // lower 1/8
0x000000ff, 0x2582, // lower 1/4
0x00000fff, 0x2583, 0x0000ffff, 0x2584, // lower 1/2
0x000fffff, 0x2585, 0x00ffffff, 0x2586, // lower 3/4
0x0fffffff, 0x2587,
// 0xffffffff, 0x2588, // full; redundant with inverse space
0xeeeeeeee, 0x258a, // left 3/4
0xcccccccc, 0x258c, // left 1/2
0x88888888, 0x258e, // left 1/4
0x0000cccc, 0x2596, // quadrant lower left
0x00003333, 0x2597, // quadrant lower right
0xcccc0000,
0x2598, // quadrant upper left
// 0xccccffff, 0x2599, // 3/4 redundant with inverse 1/4
0xcccc3333, 0x259a, // diagonal 1/2
// 0xffffcccc, 0x259b, // 3/4 redundant
// 0xffff3333, 0x259c, // 3/4 redundant
0x33330000, 0x259d, // quadrant upper right
// 0x3333cccc, 0x259e, // 3/4 redundant
// 0x3333ffff, 0x259f, // 3/4 redundant
// Line drawing subset: no double lines, no complex light lines
0x000ff000, 0x2501, // Heavy horizontal
0x66666666, 0x2503, // Heavy vertical
0x00077666, 0x250f, // Heavy down and right
0x000ee666, 0x2513, // Heavy down and left
0x66677000, 0x2517, // Heavy up and right
0x666ee000, 0x251b, // Heavy up and left
0x66677666, 0x2523, // Heavy vertical and right
0x666ee666, 0x252b, // Heavy vertical and left
0x000ff666, 0x2533, // Heavy down and horizontal
0x666ff000, 0x253b, // Heavy up and horizontal
0x666ff666, 0x254b, // Heavy cross
0x000cc000, 0x2578, // Bold horizontal left
0x00066000, 0x2579, // Bold horizontal up
0x00033000, 0x257a, // Bold horizontal right
0x00066000, 0x257b, // Bold horizontal down
0x06600660, 0x254f, // Heavy double dash vertical
0x000f0000, 0x2500, // Light horizontal
0x0000f000, 0x2500, //
0x44444444, 0x2502, // Light vertical
0x22222222, 0x2502,
0x000e0000, 0x2574, // light left
0x0000e000, 0x2574, // light left
0x44440000, 0x2575, // light up
0x22220000, 0x2575, // light up
0x00030000, 0x2576, // light right
0x00003000, 0x2576, // light right
0x00004444, 0x2577, // light down
0x00002222, 0x2577, // light down
// Misc technical
0x44444444, 0x23a2, // [ extension
0x22222222, 0x23a5, // ] extension
0x0f000000, 0x23ba, // Horizontal scanline 1
0x00f00000, 0x23bb, // Horizontal scanline 3
0x00000f00, 0x23bc, // Horizontal scanline 7
0x000000f0, 0x23bd, // Horizontal scanline 9
// Geometrical shapes. Tricky because some of them are too wide.
// 0x00ffff00, 0x25fe, // Black medium small square
0x00066000, 0x25aa, // Black small square
// 0x11224488, 0x2571, // diagonals
// 0x88442211, 0x2572,
// 0x99666699, 0x2573,
// 0x000137f0, 0x25e2, // Triangles
// 0x0008cef0, 0x25e3,
// 0x000fec80, 0x25e4,
// 0x000f7310, 0x25e5,
0, 0, // End marker for "regular" characters
// Teletext / legacy graphics 3x2 block character codes.
// Using a 3-2-3 pattern consistently, perhaps we should create automatic
// variations....
0xccc00000, 0xfb00, 0x33300000, 0xfb01, 0xfff00000, 0xfb02, 0x000cc000,
0xfb03, 0xccccc000, 0xfb04, 0x333cc000, 0xfb05, 0xfffcc000, 0xfb06,
0x00033000, 0xfb07, 0xccc33000, 0xfb08, 0x33333000, 0xfb09, 0xfff33000,
0xfb0a, 0x000ff000, 0xfb0b, 0xcccff000, 0xfb0c, 0x333ff000, 0xfb0d,
0xfffff000, 0xfb0e, 0x00000ccc, 0xfb0f,
0xccc00ccc, 0xfb10, 0x33300ccc, 0xfb11, 0xfff00ccc, 0xfb12, 0x000ccccc,
0xfb13, 0x333ccccc, 0xfb14, 0xfffccccc, 0xfb15, 0x00033ccc, 0xfb16,
0xccc33ccc, 0xfb17, 0x33333ccc, 0xfb18, 0xfff33ccc, 0xfb19, 0x000ffccc,
0xfb1a, 0xcccffccc, 0xfb1b, 0x333ffccc, 0xfb1c, 0xfffffccc, 0xfb1d,
0x00000333, 0xfb1e, 0xccc00333, 0xfb1f,
0x33300333, 0x1b20, 0xfff00333, 0x1b21, 0x000cc333, 0x1b22, 0xccccc333,
0x1b23, 0x333cc333, 0x1b24, 0xfffcc333, 0x1b25, 0x00033333, 0x1b26,
0xccc33333, 0x1b27, 0xfff33333, 0x1b28, 0x000ff333, 0x1b29, 0xcccff333,
0x1b2a, 0x333ff333, 0x1b2b, 0xfffff333, 0x1b2c, 0x00000fff, 0x1b2d,
0xccc00fff, 0x1b2e, 0x33300fff, 0x1b2f,
0xfff00fff, 0x1b30, 0x000ccfff, 0x1b31, 0xcccccfff, 0x1b32, 0x333ccfff,
0x1b33, 0xfffccfff, 0x1b34, 0x00033fff, 0x1b35, 0xccc33fff, 0x1b36,
0x33333fff, 0x1b37, 0xfff33fff, 0x1b38, 0x000fffff, 0x1b39, 0xcccfffff,
0x1b3a, 0x333fffff, 0x1b3b,
0, 1 // End marker for extended TELETEXT mode.
};
struct CharData {
std::array<int, 3> fgColor = std::array<int, 3>{0, 0, 0};
std::array<int, 3> bgColor = std::array<int, 3>{0, 0, 0};
int codePoint;
};
// Return a CharData struct with the given code point and corresponding averag
// fg and bg colors.
CharData createCharData(const cimg_library::CImg<unsigned char> &image, int x0,
int y0, int codepoint, int pattern) {
CharData result;
result.codePoint = codepoint;
int fg_count = 0;
int bg_count = 0;
unsigned int mask = 0x80000000;
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
int *avg;
if (pattern & mask) {
avg = result.fgColor.data();
fg_count++;
} else {
avg = result.bgColor.data();
bg_count++;
}
for (int i = 0; i < 3; i++) {
avg[i] += image(x0 + x, y0 + y, 0, i);
}
mask = mask >> 1;
}
}
// Calculate the average color value for each bucket
for (int i = 0; i < 3; i++) {
if (bg_count != 0) {
result.bgColor[i] /= bg_count;
}
if (fg_count != 0) {
result.fgColor[i] /= fg_count;
}
}
return result;
}
/**
* @brief Find the best character and colors
* for a 4x8 part of the image at the given position
*
* @param image
* @param x0
* @param y0
* @param flags
* @return CharData
*/
CharData findCharData(const cimg_library::CImg<unsigned char> &image, int x0,
int y0, const int &flags) {
int min[3] = {255, 255, 255};
int max[3] = {0};
std::map<long, int> count_per_color;
// Determine the minimum and maximum value for each color channel
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
long color = 0;
for (int i = 0; i < 3; i++) {
int d = image(x0 + x, y0 + y, 0, i);
min[i] = std::min(min[i], d);
max[i] = std::max(max[i], d);
color = (color << 8) | d;
}
count_per_color[color]++;
}
}
std::multimap<int, long> color_per_count;
for (auto i = count_per_color.begin(); i != count_per_color.end(); ++i) {
color_per_count.insert(std::pair<int, long>(i->second, i->first));
}
auto iter = color_per_count.rbegin();
int count2 = iter->first;
long max_count_color_1 = iter->second;
long max_count_color_2 = max_count_color_1;
if ((++iter) != color_per_count.rend()) {
count2 += iter->first;
max_count_color_2 = iter->second;
}
unsigned int bits = 0;
bool direct = count2 > (8 * 4) / 2;
if (direct) {
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
bits = bits << 1;
int d1 = 0;
int d2 = 0;
for (int i = 0; i < 3; i++) {
int shift = 16 - 8 * i;
int c1 = (max_count_color_1 >> shift) & 255;
int c2 = (max_count_color_2 >> shift) & 255;
int c = image(x0 + x, y0 + y, 0, i);
d1 += (c1 - c) * (c1 - c);
d2 += (c2 - c) * (c2 - c);
}
if (d1 > d2) {
bits |= 1;
}
}
}
} else {
// Determine the color channel with the greatest range.
int splitIndex = 0;
int bestSplit = 0;
for (int i = 0; i < 3; i++) {
if (max[i] - min[i] > bestSplit) {
bestSplit = max[i] - min[i];
splitIndex = i;
}
}
// We just split at the middle of the interval instead of computing the
// median.
int splitValue = min[splitIndex] + bestSplit / 2;
// Compute a bitmap using the given split and sum the color values for
// both buckets.
for (int y = 0; y < 8; y++) {
for (int x = 0; x < 4; x++) {
bits = bits << 1;
if (image(x0 + x, y0 + y, 0, splitIndex) > splitValue) {
bits |= 1;
}
}
}
}
// Find the best bitmap match by counting the bits that don't match,
// including the inverted bitmaps.
int best_diff = 8;
unsigned int best_pattern = 0x0000ffff;
int codepoint = 0x2584;
bool inverted = false;
unsigned int end_marker = flags & FLAG_TELETEXT ? 1 : 0;
for (int i = 0; BITMAPS[i + 1] != end_marker; i += 2) {
// Skip all end markers
if (BITMAPS[i + 1] < 32) {
continue;
}
unsigned int pattern = BITMAPS[i];
for (int j = 0; j < 2; j++) {
int diff = (std::bitset<32>(pattern ^ bits)).count();
if (diff < best_diff) {
best_pattern = BITMAPS[i]; // pattern might be inverted.
codepoint = BITMAPS[i + 1];
best_diff = diff;
inverted = best_pattern != pattern;
}
pattern = ~pattern;
}
}
if (direct) {
CharData result;
if (inverted) {
long tmp = max_count_color_1;
max_count_color_1 = max_count_color_2;
max_count_color_2 = tmp;
}
for (int i = 0; i < 3; i++) {
int shift = 16 - 8 * i;
result.fgColor[i] = (max_count_color_2 >> shift) & 255;
result.bgColor[i] = (max_count_color_1 >> shift) & 255;
result.codePoint = codepoint;
}
return result;
}
return createCharData(image, x0, y0, codepoint, best_pattern);
}
int clamp_byte(int value) {
return value < 0 ? 0 : (value > 255 ? 255 : value);
}
double sqr(double n) { return n * n; }
int best_index(int value, const int (&STEPS)[], int count) {
int best_diff = std::abs(STEPS[0] - value);
int result = 0;
for (int i = 1; i < count; i++) {
int diff = std::abs(STEPS[i] - value);
if (diff < best_diff) {
result = i;
best_diff = diff;
}
}
return result;
}
void emit_color(const int &flags, int r, int g, int b) {
r = clamp_byte(r);
g = clamp_byte(g);
b = clamp_byte(b);
bool bg = (flags & FLAG_BG) != 0;
if ((flags & FLAG_MODE_256) == 0) {
std::cout << (bg ? "\x1b[48;2;" : "\x1b[38;2;") << r << ';' << g << ';'
<< b << 'm';
return;
}
int ri = best_index(r, COLOR_STEPS, COLOR_STEP_COUNT);
int gi = best_index(g, COLOR_STEPS, COLOR_STEP_COUNT);
int bi = best_index(b, COLOR_STEPS, COLOR_STEP_COUNT);
int rq = COLOR_STEPS[ri];
int gq = COLOR_STEPS[gi];
int bq = COLOR_STEPS[bi];
int gray =
static_cast<int>(std::round(r * 0.2989f + g * 0.5870f + b * 0.1140f));
int gri = best_index(gray, GRAYSCALE_STEPS, GRAYSCALE_STEP_COUNT);
int grq = GRAYSCALE_STEPS[gri];
int color_index;
if (0.3 * sqr(rq - r) + 0.59 * sqr(gq - g) + 0.11 * sqr(bq - b) <
0.3 * sqr(grq - r) + 0.59 * sqr(grq - g) + 0.11 * sqr(grq - b)) {
color_index = 16 + 36 * ri + 6 * gi + bi;
} else {
color_index = 232 + gri; // 1..24 -> 232..255
}
std::cout << (bg ? "\x1B[48;5;" : "\u001B[38;5;") << color_index << "m";
}
void emitCodepoint(int codepoint) {
if (codepoint < 128) {
std::cout << static_cast<char>(codepoint);
} else if (codepoint < 0x7ff) {
std::cout << static_cast<char>(0xc0 | (codepoint >> 6));
std::cout << static_cast<char>(0x80 | (codepoint & 0x3f));
} else if (codepoint < 0xffff) {
std::cout << static_cast<char>(0xe0 | (codepoint >> 12));
std::cout << static_cast<char>(0x80 | ((codepoint >> 6) & 0x3f));
std::cout << static_cast<char>(0x80 | (codepoint & 0x3f));
} else if (codepoint < 0x10ffff) {
std::cout << static_cast<char>(0xf0 | (codepoint >> 18));
std::cout << static_cast<char>(0x80 | ((codepoint >> 12) & 0x3f));
std::cout << static_cast<char>(0x80 | ((codepoint >> 6) & 0x3f));
std::cout << static_cast<char>(0x80 | (codepoint & 0x3f));
} else {
std::cerr << "ERROR";
}
}
void emit_image(const cimg_library::CImg<unsigned char> &image,
const int &flags) {
CharData lastCharData;
for (int y = 0; y <= image.height() - 8; y += 8) {
for (int x = 0; x <= image.width() - 4; x += 4) {
CharData charData =
flags & FLAG_NOOPT
? createCharData(image, x, y, 0x2584, 0x0000ffff)
: findCharData(image, x, y, flags);
if (x == 0 || charData.bgColor != lastCharData.bgColor)
emit_color(flags | FLAG_BG, charData.bgColor[0],
charData.bgColor[1], charData.bgColor[2]);
if (x == 0 || charData.fgColor != lastCharData.fgColor)
emit_color(flags | FLAG_FG, charData.fgColor[0],
charData.fgColor[1], charData.fgColor[2]);
emitCodepoint(charData.codePoint);
lastCharData = charData;
}
std::cout << "\x1b[0m" << std::endl;
}
}
struct size {
size(unsigned int in_width, unsigned int in_height)
: width(in_width), height(in_height) {}
explicit size(cimg_library::CImg<unsigned int> img)
: width(img.width()), height(img.height()) {}
unsigned int width;
unsigned int height;
size scaled(double scale) { return size(width * scale, height * scale); }
size fitted_within(size container) {
double scale = std::min(container.width / static_cast<double>(width),
container.height / static_cast<double>(height));
return scaled(scale);
}
};
std::ostream &operator<<(std::ostream &stream, size sz) {
stream << sz.width << "x" << sz.height;
return stream;
}
/**
* @brief Wrapper around CImg<T>(const char*) constructor
* that always returns a CImg image with 3 channels (RGB)
*
* @param filename The file to construct a CImg object on
* @return cimg_library::CImg<unsigned char> Constructed CImg RGB image
*/
cimg_library::CImg<unsigned char> load_rgb_CImg(const char *const &filename) {
cimg_library::CImg<unsigned char> image(filename);
if (image.spectrum() == 1) {
// Greyscale. Just copy greyscale data to all channels
cimg_library::CImg<unsigned char> rgb_image(
image.width(), image.height(), image.depth(), 3);
for (unsigned int chn = 0; chn < 3; chn++) {
rgb_image.draw_image(0, 0, 0, chn, image);
}
return rgb_image;
}
return image;
}
// Implements --help
void emit_usage() {
std::cerr << R"(
Terminal Image Viewer v1.2
usage: tiv [options] <image> [<image>...]
-0 : No block character adjustment, always use top half block char.
-2, --256 : Use 256-bit colors. Needed to display properly on macOS Terminal.
-c <num> : Number of thumbnail columns in 'dir' mode (3 by default).
-d, --dir : Force 'dir' mode. Automatially selected for more than one input.
-f, --full: Force 'full' mode. Automatically selected for one input.
--help : Display this help text.
-h <num> : Set the maximum output height to <num> lines.
-w <num> : Set the maximum output width to <num> characters.
-x : Use new Unicode Teletext/legacy characters (experimental).)"
<< std::endl;
}
enum Mode { AUTO, THUMBNAILS, FULL_SIZE };
int main(int argc, char *argv[]) {
std::ios::sync_with_stdio(false); // apparently makes printing faster
// Platform-specific implementations for determining console size, better
// implementations are welcome Fallback sizes when unsuccesful
int maxWidth = 80;
int maxHeight = 24;
#ifdef __POSIX_VERSION
struct winsize w;
// If redirecting STDOUT to one file ( col or row == 0, or the previous
// ioctl call's failed )
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &w) != 0 ||
(w.ws_col | w.ws_row) == 0) {
std::cerr << "Warning: failed to determine most reasonable size, "
"defaulting to 80x24"
<< std::endl;
} else {
maxWidth = w.ws_col * 4;
maxHeight = w.ws_row * 8;
}
#elif defined _WIN32
CONSOLE_SCREEN_BUFFER_INFO w;
if (GetConsoleScreenBufferInfo(
GetStdHandle(STD_OUTPUT_HANDLE),
&w)) { // just like powershell, but without the hyphens, hooray
maxWidth = w.dwSize.X * 4;
maxHeight = w.dwSize.Y * 8;
} else {
std::cerr << GetLastError();
std::cerr << "Warning: failed to determine most reasonable size, "
"defaulting to 80x24"
<< std::endl;
}
#else
std::cerr << "Warning: failed to determine most reasonable sie: "
"unrecognized system, defaulting to 80x24"
<< std::endl;
#endif
// Reading input
char flags = 0; // bitwise representation of flags,
// see https://stackoverflow.com/a/14295472
Mode mode = AUTO; // either THUMBNAIL or FULL_SIZE
int columns = 3;
std::vector<std::string> file_names;
int ret = EX_OK; // The return code for the program
if (argc <= 1) {
emit_usage();
return 0;
}
for (int i = 1; i < argc; i++) {
std::string arg(argv[i]);
if (arg == "-0") {
flags |= FLAG_NOOPT;
} else if (arg == "-c") {
if (i < argc - 1) {
columns = std::stoi(argv[++i]);
} else {
std::cerr << "Error: -c requires a number" << std::endl;
ret = EX_USAGE;
}
} else if (arg == "-d" || arg == "--dir") {
mode = THUMBNAILS;
} else if (arg == "-f" || arg == "--full") {
mode = FULL_SIZE;
} else if (arg == "-w") {
if (i < argc - 1) {
maxWidth = 4 * std::stoi(argv[++i]);
} else {
std::cerr << "Error: -w requires a number" << std::endl;
ret = EX_USAGE;
}
} else if (arg == "-h") {
if (i < argc - 1)
maxHeight = 8 * std::stoi(argv[++i]);
else
emit_usage();
} else if (arg == "--256" || arg == "-2" || arg == "-256") {
flags |= FLAG_MODE_256;
} else if (arg == "--help" || arg == "-help") {
emit_usage();
} else if (arg == "-x") {
flags |= FLAG_TELETEXT;
} else if (arg[0] == '-') {
std::cerr << "Error: Unrecognized argument: " << arg << std::endl;
ret = EX_USAGE;
} else {
// Arguments that will be displayed
if (std::filesystem::is_directory(arg)) {
for (auto &p : std::filesystem::directory_iterator(arg))
if (std::filesystem::is_regular_file(p.path()))
file_names.push_back(p.path().string());
} else {
// Check if file can be opened
std::ifstream fin(arg.c_str());
if (fin) {
file_names.push_back(arg);
} else {
std::cerr << "Error: Cannot open '" << arg
<< "', permission issue?" << std::endl;
ret = EX_NOINPUT;
}
}
}
}
if (mode == FULL_SIZE || (mode == AUTO && file_names.size() == 1)) {
for (const auto &filename : file_names) {
try {
cimg_library::CImg<unsigned char> image =
load_rgb_CImg(filename.c_str());
if (image.width() > maxWidth || image.height() > maxHeight) {
// scale image down to fit terminal size
size new_size =
size(image).fitted_within(size(maxWidth, maxHeight));
image.resize(new_size.width, new_size.height, -100, -100,
5);
}
// the acutal magic which generates the output
emit_image(image, flags);
} catch (cimg_library::CImgIOException &e) {
std::cerr << "Error: '" << filename
<< "' has an unrecognized file format" << std::endl;
ret = EX_DATAERR;
}
}
} else { // Thumbnail mode
unsigned int index = 0;
int cw = (((maxWidth / 4) - 2 * (columns - 1)) / columns);
int tw = cw * 4;
cimg_library::CImg<unsigned char> image(
tw * columns + 2 * 4 * (columns - 1), tw, 1, 3);
size maxThumbSize(tw, tw);
while (index < file_names.size()) {
image.fill(0);
int count = 0;
std::string sb;
while (index < file_names.size() && count < columns) {
std::string name = file_names[index++];
try {
cimg_library::CImg<unsigned char> original =
load_rgb_CImg(name.c_str());
auto cut = name.find_last_of("/");
sb +=
cut == std::string::npos ? name : name.substr(cut + 1);
size newSize = size(original).fitted_within(maxThumbSize);
original.resize(newSize.width, newSize.height, 1, -100, 5);
image.draw_image(
count * (tw + 8) + (tw - newSize.width) / 2,
(tw - newSize.height) / 2, 0, 0, original);
count++;
unsigned int sl = count * (cw + 2);
sb.resize(sl - 2, ' ');
sb += " ";
} catch (std::exception &e) {
// Probably no image; ignore.
}
}
if (count) emit_image(image, flags);
std::cout << sb << std::endl << std::endl;
}
}
return ret;
}