Added dithering and improved performance

README.md

@@ -1,10 +1,10 @@
 # ascii-image-converter
 
-[![release version](https://img.shields.io/github/v/release/TheZoraiz/ascii-image-converter?label=Latest%20Version)](https://github.com/TheZoraiz/ascii-image-converter/releases/latest)
+[![release-version](https://img.shields.io/github/v/release/TheZoraiz/ascii-image-converter?label=Latest%20Version)](https://github.com/TheZoraiz/ascii-image-converter/releases/latest)
-[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://github.com/TheZoraiz/ascii-image-converter/blob/master/LICENSE.txt)
+[![license](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://github.com/TheZoraiz/ascii-image-converter/blob/master/LICENSE.txt)
-[![ascii-image-converter-lang](https://img.shields.io/badge/Language-Go-blue)](https://golang.org/) 
+[![language](https://img.shields.io/badge/Language-Go-blue)](https://golang.org/) 
-![Github All Releases](https://img.shields.io/github/downloads/TheZoraiz/ascii-image-converter/total?color=brightgreen&label=Release%20Downloads)
+![release-downloads](https://img.shields.io/github/downloads/TheZoraiz/ascii-image-converter/total?color=1d872d&label=Release%20Downloads)
-[![ascii-image-converter](https://snapcraft.io/ascii-image-converter/badge.svg)](https://snapcraft.io/ascii-image-converter)  
+[![ascii-image-converter-snap](https://snapcraft.io/ascii-image-converter/badge.svg)](https://snapcraft.io/ascii-image-converter)
 
 ascii-image-converter is a command-line tool that converts images into ascii art and prints them out onto the console. Available on Windows, Linux and macOS.
 
@@ -135,8 +135,7 @@ Now you can use ascii-image-converter in the terminal. Execute `ascii-image-conv
 You will need to set an Environment Variable to the folder the ascii-image-converter.exe executable is placed in to be able to use it in the command prompt. Follow the instructions in case of confusion:
 
 Download the archive for your Windows architecture [here](https://github.com/TheZoraiz/ascii-image-converter/releases/latest), extract it, and open the extracted folder. Now, copy the folder path from the top of the file explorer and follow these instructions:
-* In Search, search for and then select: System (Control Panel)
+* In Search, search for and then select: Advanced System Settings
-* Click the Advanced System settings link.
 * Click Environment Variables. In the section User Variables find the Path environment variable and select it. Click "Edit".
 * In the Edit Environment Variable window, click "New" and then paste the path of the folder that you copied initially.
 * Click "Ok" on all open windows.
@@ -199,6 +198,19 @@ Example:
 ascii-image-converter [image paths/urls] -b --threshold 170
 ```
 
+#### --dither
+
+Apply dithering on image to make braille art more visible. Since braille dots can only be on or off, dithering images makes them more visible in braille art.
+
+Example:
+```
+ascii-image-converter [image paths/urls] -b --dither
+```
+
+<p align="center">
+  <img src="https://raw.githubusercontent.com/TheZoraiz/ascii-image-converter/master/example_gifs/dither.gif">
+</p>
+
 #### --color-bg
 
 If any of the coloring flags is passed, this flag will transfer its color to each character's background. instead of foreground. However, this option isn't available for `--save-img` and `--save-gif`
@@ -492,6 +504,8 @@ You can fork the project and implement any changes you want for a pull request.
 
 [github.com/asaskevich/govalidator](https://github.com/asaskevich/govalidator)
 
+[github.com/makeworld-the-better-one/dither/v2](https://github.com/makeworld-the-better-one/dither/v2)
+
 ## License
 
 [Apache-2.0](https://github.com/TheZoraiz/ascii-image-converter/blob/master/LICENSE.txt)

aic_package/convert_gif.go

@@ -97,7 +97,7 @@ func pathIsGif(gifPath, urlImgName string, pathIsURl bool, urlImgBytes []byte, l
 
 			var imgSet [][]imgManip.AsciiPixel
 
-			imgSet, err = imgManip.ConvertToAsciiPixels(frameImage, dimensions, width, height, flipX, flipY, full, braille)
+			imgSet, err = imgManip.ConvertToAsciiPixels(frameImage, dimensions, width, height, flipX, flipY, full, braille, dither)
 			if err != nil {
 				fmt.Println("Error:", err)
 				os.Exit(0)

aic_package/convert_image.go

@@ -43,7 +43,7 @@ func pathIsImage(imagePath, urlImgName string, pathIsURl bool, urlImgBytes []byt
 		return "", fmt.Errorf("can't decode %v: %v", imagePath, err)
 	}
 
-	imgSet, err := imgManip.ConvertToAsciiPixels(imData, dimensions, width, height, flipX, flipY, full, braille)
+	imgSet, err := imgManip.ConvertToAsciiPixels(imData, dimensions, width, height, flipX, flipY, full, braille, dither)
 	if err != nil {
 		return "", err
 	}

aic_package/convert_root.go

@@ -60,6 +60,7 @@ func DefaultFlags() Flags {
 		SaveBackgroundColor: [3]int{0, 0, 0},
 		Braille:             false,
 		Threshold:           128,
+		Dither:              false,
 	}
 }
 
@@ -94,6 +95,7 @@ func Convert(filePath string, flags Flags) (string, error) {
 	saveBgColor = flags.SaveBackgroundColor
 	braille = flags.Braille
 	threshold = flags.Threshold
+	dither = flags.Dither
 
 	// Declared at the start since some variables are initially used in conditional blocks
 	var (

aic_package/vars.go

@@ -94,6 +94,10 @@ type Flags struct {
 	// be between 0 and 255. Ideal value is 128.
 	// This will be ignored if Flags.Braille is not set
 	Threshold int
+
+	// Apply FloydSteinberg dithering on an image before ascii conversion. This option
+	// is meant for braille art. Therefore, it will be ignored if Flags.Braille is false
+	Dither bool
 }
 
 var (
@@ -117,4 +121,5 @@ var (
 	saveBgColor   [3]int
 	braille       bool
 	threshold     int
+	dither        bool
 )

cmd/root.go

@@ -51,12 +51,13 @@ var (
 	saveBgColor   []int
 	braille       bool
 	threshold     int
+	dither        bool
 
 	// Root commands
 	rootCmd = &cobra.Command{
 		Use:     "ascii-image-converter [image paths/urls]",
 		Short:   "Converts images and gifs into ascii art",
-		Version: "1.8.0",
+		Version: "1.9.0",
 		Long:    "This tool converts images into ascii art and prints them on the terminal.\nFurther configuration can be managed with flags.",
 
 		// Not RunE since help text is getting larger and seeing it for every error impacts user experience
@@ -87,6 +88,7 @@ var (
 				SaveBackgroundColor: [3]int{saveBgColor[0], saveBgColor[1], saveBgColor[2]},
 				Braille:             braille,
 				Threshold:           threshold,
+				Dither:              dither,
 			}
 
 			for _, imagePath := range args {
@@ -126,13 +128,14 @@ func init() {
 
 	// rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.ascii-image-converter.yaml)")
 	rootCmd.PersistentFlags().BoolVarP(&colored, "color", "C", false, "Display ascii art with original colors\n(Inverts with --negative flag)\n(Overrides --grayscale and --font-color flags)\n")
-	rootCmd.PersistentFlags().BoolVar(&colorBg, "color-bg", false, "If some color flag is passed, use that color\non character background instead of foreground\n(Inverts with --negative flag)\n(Doesn't work for --save-img or --save-gif)\n")
+	rootCmd.PersistentFlags().BoolVar(&colorBg, "color-bg", false, "If some color flag is passed, use that color\non character background instead of foreground\n(Inverts with --negative flag)\n(Only applicable for terminal display)\n")
 	rootCmd.PersistentFlags().IntSliceVarP(&dimensions, "dimensions", "d", nil, "Set width and height for ascii art in CHARACTER length\ne.g. -d 60,30 (defaults to terminal height)\n(Overrides --width and --height flags)\n")
 	rootCmd.PersistentFlags().IntVarP(&width, "width", "W", 0, "Set width for ascii art in CHARACTER length\nHeight is kept to aspect ratio\ne.g. -W 60\n")
 	rootCmd.PersistentFlags().IntVarP(&height, "height", "H", 0, "Set height for ascii art in CHARACTER length\nWidth is kept to aspect ratio\ne.g. -H 60\n")
 	rootCmd.PersistentFlags().StringVarP(&customMap, "map", "m", "", "Give custom ascii characters to map against\nOrdered from darkest to lightest\ne.g. -m \" .-+#@\" (Quotation marks excluded from map)\n(Overrides --complex flag)\n")
 	rootCmd.PersistentFlags().BoolVarP(&braille, "braille", "b", false, "Use braille characters instead of ascii\nTerminal must support braille patterns properly\n(Overrides --complex and --map flags)\n")
 	rootCmd.PersistentFlags().IntVar(&threshold, "threshold", 0, "Threshold for braille art\nValue between 0-255 is accepted\ne.g. --threshold 170\n(Defaults to 128)\n")
+	rootCmd.PersistentFlags().BoolVar(&dither, "dither", false, "Apply dithering on image for braille\nart conversion\n(Only applicable with --braille flag)\n(Negates --threshold flag)\n")
 	rootCmd.PersistentFlags().BoolVarP(&grayscale, "grayscale", "g", false, "Display grayscale ascii art\n(Inverts with --negative flag)\n(Overrides --font-color flag)\n")
 	rootCmd.PersistentFlags().BoolVarP(&complex, "complex", "c", false, "Display ascii characters in a larger range\nMay result in higher quality\n")
 	rootCmd.PersistentFlags().BoolVarP(&full, "full", "f", false, "Use largest dimensions for ascii art\nthat fill the terminal width\n(Overrides --dimensions, --width and --height flags)\n")

cmd/util.go

@@ -180,5 +180,10 @@ func checkInputAndFlags(args []string) bool {
 		return true
 	}
 
+	if dither && !braille {
+		fmt.Printf("Error: image dithering is only reserved for --braille flag\n\n")
+		return true
+	}
+
 	return false
 }

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
 	github.com/gookit/color v1.4.2
 	github.com/magiconair/properties v1.8.5 // indirect
+	github.com/makeworld-the-better-one/dither/v2 v2.2.0
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mitchellh/mapstructure v1.4.1 // indirect
 	github.com/nathan-fiscaletti/consolesize-go v0.0.0-20210105204122-a87d9f614b9d

go.sum

@@ -124,6 +124,8 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/magiconair/properties v1.8.5 h1:b6kJs+EmPFMYGkow9GiUyCyOvIwYetYJ3fSaWak/Gls=
 github.com/magiconair/properties v1.8.5/go.mod h1:y3VJvCyxH9uVvJTWEGAELF3aiYNyPKd5NZ3oSwXrF60=
+github.com/makeworld-the-better-one/dither/v2 v2.2.0 h1:VTMAiyyO1YIO07fZwuLNZZasJgKUmvsIA48ze3ALHPQ=
+github.com/makeworld-the-better-one/dither/v2 v2.2.0/go.mod h1:VBtN8DXO7SNtyGmLiGA7IsFeKrBkQPze1/iAeM95arc=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=

image_manipulation/image_conversions.go

@@ -17,12 +17,8 @@ limitations under the License.
 package image_conversions
 
 import (
-	"fmt"
 	"image"
 	"image/color"
-
-	"github.com/TheZoraiz/ascii-image-converter/aic_package/winsize"
-	"github.com/disintegration/imaging"
 )
 
 type AsciiPixel struct {
@@ -31,131 +27,26 @@ type AsciiPixel struct {
 	rgbValue       [3]uint32
 }
 
-func resizeForBraille(asciiWidth, asciiHeight int) (int, int) {
-	return asciiWidth * 2, asciiHeight * 4
-}
-
 /*
-This function shrinks the passed image according to passed dimensions or terminal
+This function shrinks the passed image according to specified or default dimensions.
-size if none are passed. Stores each pixel's grayscale and RGB values in an AsciiPixel
+Stores each pixel's grayscale and RGB values in an AsciiPixel instance to simplify
-instance to simplify getting numeric data for ASCII character comparison.
+getting numeric data for ASCII character comparison.
 
-The returned 2D AsciiPixel slice contains each corresponding pixel's values. Grayscale value
+The returned 2D AsciiPixel slice contains each corresponding pixel's values
-ranges from 0 to 65535, while RGB values are separate.
 */
-func ConvertToAsciiPixels(img image.Image, dimensions []int, width, height int, flipX, flipY, full, isBraille bool) ([][]AsciiPixel, error) {
+func ConvertToAsciiPixels(img image.Image, dimensions []int, width, height int, flipX, flipY, full, isBraille, dither bool) ([][]AsciiPixel, error) {
 
-	var asciiWidth, asciiHeight int
+	smallImg, err := resizeImage(img, full, isBraille, dimensions, width, height)
-	var smallImg image.Image
-
-	terminalWidth, terminalHeight, err := winsize.GetTerminalSize()
 	if err != nil {
 		return nil, err
 	}
 
-	if full {
+	// We mainatin a dithered image literal along with original image
-		asciiWidth = terminalWidth - 1
+	// The colors are kept from original image
+	var ditheredImage image.Image
 
-		// Passing 0 in place of width keeps the original image's aspect ratio
+	if isBraille && dither {
-		smallImg = imaging.Resize(img, asciiWidth, 0, imaging.Lanczos)
+		ditheredImage = ditherImage(smallImg)
-		asciiHeight = smallImg.Bounds().Max.Y - smallImg.Bounds().Min.Y
-
-		// To fix aspect ratio in eventual ascii art
-		asciiHeight = int(0.5 * float64(asciiHeight))
-
-		if isBraille {
-			asciiWidth, asciiHeight = resizeForBraille(asciiWidth, asciiHeight)
-		}
-		smallImg = imaging.Resize(img, asciiWidth, asciiHeight, imaging.Lanczos)
-
-	} else if (width != 0 || height != 0) && len(dimensions) == 0 {
-		// If either width or height is set and dimensions aren't given
-
-		if width > terminalWidth-1 {
-			return nil, fmt.Errorf("set width must be lower than terminal width")
-		}
-
-		if width != 0 && height == 0 {
-			// If width is set and height is not set, use width to calculate aspect ratio
-
-			asciiWidth = width
-
-			smallImg = imaging.Resize(img, asciiWidth, 0, imaging.Lanczos)
-			asciiHeight = smallImg.Bounds().Max.Y - smallImg.Bounds().Min.Y
-
-			asciiHeight = int(0.5 * float64(asciiHeight))
-			if asciiHeight == 0 {
-				asciiHeight = 1
-			}
-
-		} else if height != 0 && width == 0 {
-			// If height is set and width is not set, use height to calculate aspect ratio
-
-			asciiHeight = height
-
-			smallImg = imaging.Resize(img, 0, asciiHeight, imaging.Lanczos)
-			asciiWidth = smallImg.Bounds().Max.X - smallImg.Bounds().Min.X
-
-			asciiWidth = int(2 * float64(asciiWidth))
-
-			if asciiWidth > terminalWidth-1 {
-				return nil, fmt.Errorf("width calculated with aspect ratio exceeds terminal width")
-			}
-
-		} else {
-			return nil, fmt.Errorf("both width and height can't be set. Use dimensions instead")
-		}
-
-		if isBraille {
-			asciiWidth, asciiHeight = resizeForBraille(asciiWidth, asciiHeight)
-		}
-		smallImg = imaging.Resize(img, asciiWidth, asciiHeight, imaging.Lanczos)
-
-	} else if len(dimensions) == 0 {
-		// This condition calculates aspect ratio according to terminal height
-
-		asciiHeight = terminalHeight - 1
-
-		smallImg = imaging.Resize(img, 0, asciiHeight, imaging.Lanczos)
-		asciiWidth = smallImg.Bounds().Max.X - smallImg.Bounds().Min.X
-
-		// To fix aspect ratio in eventual ascii art
-		asciiWidth = int(2 * float64(asciiWidth))
-
-		// If ascii width exceeds terminal width, change ratio with respect to terminal width
-		if asciiWidth >= terminalWidth {
-			asciiWidth = terminalWidth - 1
-
-			smallImg = imaging.Resize(img, asciiWidth, 0, imaging.Lanczos)
-
-			asciiHeight = smallImg.Bounds().Max.Y - smallImg.Bounds().Min.Y
-
-			// To fix aspect ratio in eventual ascii art
-			asciiHeight = int(0.5 * float64(asciiHeight))
-		}
-
-		if isBraille {
-			asciiWidth, asciiHeight = resizeForBraille(asciiWidth, asciiHeight)
-		}
-		smallImg = imaging.Resize(img, asciiWidth, asciiHeight, imaging.Lanczos)
-
-	} else {
-		asciiWidth = dimensions[0]
-		asciiHeight = dimensions[1]
-
-		if isBraille {
-			asciiWidth, asciiHeight = resizeForBraille(asciiWidth, asciiHeight)
-		}
-		smallImg = imaging.Resize(img, asciiWidth, asciiHeight, imaging.Lanczos)
-	}
-
-	// Repeated despite being in cmd/root.go to maintain support for library
-	//
-	// If there are passed dimensions, check whether the width exceeds terminal width
-	if len(dimensions) > 0 && !full {
-		if dimensions[0] > terminalWidth-1 {
-			return nil, fmt.Errorf("set width must be lower than terminal width")
-		}
 	}
 
 	var imgSet [][]AsciiPixel
@@ -177,6 +68,19 @@ func ConvertToAsciiPixels(img image.Image, dimensions []int, width, height int,
 			g1 = uint32(g1 / 257)
 			b1 = uint32(b1 / 257)
 
+			if isBraille && dither {
+
+				// Change charDepth if image dithering is applied
+				// 		Note that neither grayscale nor original color values are changed.
+				// 		Only charDepth is kept from dithered image. This is because a
+				// 		dithered image loses its colors so it's only used to check braille
+				// 		dots' visibility
+
+				ditheredGrayPixel := color.GrayModel.Convert(ditheredImage.At(x, y))
+				charDepth, _, _, _ = ditheredGrayPixel.RGBA()
+				charDepth = charDepth / 257
+			}
+
 			// Get co1ored RGB values of original pixel for rgbValue in AsciiPixel
 			r2, g2, b2, _ := oldPixel.RGBA()
 			r2 = uint32(r2 / 257)
@@ -200,22 +104,3 @@ func ConvertToAsciiPixels(img image.Image, dimensions []int, width, height int,
 
 	return imgSet, nil
 }
-
-func reverse(imgSet [][]AsciiPixel, flipX, flipY bool) [][]AsciiPixel {
-
-	if flipX {
-		for _, row := range imgSet {
-			for i, j := 0, len(row)-1; i < j; i, j = i+1, j-1 {
-				row[i], row[j] = row[j], row[i]
-			}
-		}
-	}
-
-	if flipY {
-		for i, j := 0, len(imgSet)-1; i < j; i, j = i+1, j-1 {
-			imgSet[i], imgSet[j] = imgSet[j], imgSet[i]
-		}
-	}
-
-	return imgSet
-}

image_manipulation/util.go

@@ -0,0 +1,151 @@
+/*
+Copyright © 2021 Zoraiz Hassan <hzoraiz8@gmail.com>
+
+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
+
+    http://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.
+*/
+
+package image_conversions
+
+import (
+	"fmt"
+	"image"
+	"image/color"
+
+	"github.com/TheZoraiz/ascii-image-converter/aic_package/winsize"
+	"github.com/disintegration/imaging"
+	"github.com/makeworld-the-better-one/dither/v2"
+)
+
+func resizeForBraille(asciiWidth, asciiHeight int) (int, int) {
+	return asciiWidth * 2, asciiHeight * 4
+}
+
+func ditherImage(img image.Image) image.Image {
+
+	palette := []color.Color{
+		color.Black,
+		color.White,
+	}
+
+	d := dither.NewDitherer(palette)
+	d.Matrix = dither.FloydSteinberg
+
+	return d.DitherCopy(img)
+}
+
+func resizeImage(img image.Image, full, isBraille bool, dimensions []int, width, height int) (image.Image, error) {
+
+	var asciiWidth, asciiHeight int
+	var smallImg image.Image
+
+	terminalWidth, terminalHeight, err := winsize.GetTerminalSize()
+	if err != nil {
+		return nil, err
+	}
+
+	imgWidth := float64(img.Bounds().Dx())
+	imgHeight := float64(img.Bounds().Dy())
+	aspectRatio := imgWidth / imgHeight
+
+	if full {
+		asciiWidth = terminalWidth - 1
+		asciiHeight = int(float64(asciiWidth) / aspectRatio)
+		asciiHeight = int(0.5 * float64(asciiHeight))
+
+	} else if (width != 0 || height != 0) && len(dimensions) == 0 {
+		// If either width or height is set and dimensions aren't given
+
+		if width > terminalWidth-1 {
+			return nil, fmt.Errorf("set width must be lower than terminal width")
+		}
+
+		if width != 0 && height == 0 {
+			// If width is set and height is not set, use width to calculate aspect ratio
+
+			asciiWidth = width
+			asciiHeight = int(float64(asciiWidth) / aspectRatio)
+			asciiHeight = int(0.5 * float64(asciiHeight))
+
+			if asciiHeight == 0 {
+				asciiHeight = 1
+			}
+
+		} else if height != 0 && width == 0 {
+			// If height is set and width is not set, use height to calculate aspect ratio
+
+			asciiHeight = height
+			asciiWidth = int(float64(asciiHeight) * aspectRatio)
+			asciiWidth = int(2 * float64(asciiWidth))
+
+			if asciiWidth > terminalWidth-1 {
+				return nil, fmt.Errorf("width calculated with aspect ratio exceeds terminal width")
+			}
+
+		} else {
+			return nil, fmt.Errorf("both width and height can't be set. Use dimensions instead")
+		}
+
+	} else if len(dimensions) == 0 {
+		// This condition calculates aspect ratio according to terminal height
+
+		asciiHeight = terminalHeight - 1
+		asciiWidth = int(float64(asciiHeight) * aspectRatio)
+		asciiWidth = int(2 * float64(asciiWidth))
+
+		// If ascii width exceeds terminal width, change ratio with respect to terminal width
+		if asciiWidth >= terminalWidth {
+			asciiWidth = terminalWidth - 1
+			asciiHeight = int(float64(asciiWidth) / aspectRatio)
+			asciiHeight = int(0.5 * float64(asciiHeight))
+		}
+
+	} else {
+		asciiWidth = dimensions[0]
+		asciiHeight = dimensions[1]
+	}
+
+	// Repeated despite being in cmd/root.go to maintain support for library
+	//
+	// If there are passed dimensions, check whether the width exceeds terminal width
+	if len(dimensions) > 0 && !full {
+		if dimensions[0] > terminalWidth-1 {
+			return nil, fmt.Errorf("set width must be lower than terminal width")
+		}
+	}
+
+	if isBraille {
+		asciiWidth, asciiHeight = resizeForBraille(asciiWidth, asciiHeight)
+	}
+	smallImg = imaging.Resize(img, asciiWidth, asciiHeight, imaging.Lanczos)
+
+	return smallImg, nil
+}
+
+func reverse(imgSet [][]AsciiPixel, flipX, flipY bool) [][]AsciiPixel {
+
+	if flipX {
+		for _, row := range imgSet {
+			for i, j := 0, len(row)-1; i < j; i, j = i+1, j-1 {
+				row[i], row[j] = row[j], row[i]
+			}
+		}
+	}
+
+	if flipY {
+		for i, j := 0, len(imgSet)-1; i < j; i, j = i+1, j-1 {
+			imgSet[i], imgSet[j] = imgSet[j], imgSet[i]
+		}
+	}
+
+	return imgSet
+}

snapcraft.yaml

@@ -1,6 +1,6 @@
 name: ascii-image-converter
 base: core18 
-version: "1.8.0"
+version: "1.9.0"
 summary: Convert images and gifs into ascii art
 description: |
   ascii-image-converter is a command-line tool that converts images into ascii art and prints