diff --git a/build.cmd b/build.cmd
index 24e4f66..a981f78 100644
--- a/build.cmd
+++ b/build.cmd
@@ -1,10 +1,6 @@
 @echo off
 
-if not exist bin (
-    mkdir bin
-)
-
 echo Building...
-go build -o bin/ffwebp.exe
+go build -o %USERPROFILE%/.bin/ffwebp.exe
 
-echo Done
\ No newline at end of file
+echo Done
diff --git a/ffwebp_test.go b/ffwebp_test.go
index c0c7ea1..a09f013 100644
--- a/ffwebp_test.go
+++ b/ffwebp_test.go
@@ -4,9 +4,7 @@ import (
 	"bytes"
 	"image/png"
 	"log"
-	"os/exec"
-	"path/filepath"
-	"strings"
+	"os"
 	"testing"
 )
 
@@ -28,40 +26,43 @@ var (
 )
 
 func TestFFWebP(t *testing.T) {
-	exe, err := filepath.Abs("bin/ffwebp.exe")
-	if err != nil {
-		log.Fatalf("Failed to get absolute path for ffwebp.exe: %v\n", err)
-	}
+	opts.Silent = true
 
 	for _, file := range TestFiles {
 		log.Printf("Testing file: %s\n", file)
 
-		cmd := exec.Command(exe, "-i", file, "-f", "png", "-s")
-
-		// Capture the output (which is expected to be a PNG image)
-		var stdout bytes.Buffer
-
-		cmd.Stdout = &stdout
-
-		// Run the command
-		err := cmd.Run()
+		in, err := os.OpenFile(file, os.O_RDONLY, 0)
 		if err != nil {
-			out := strings.TrimSpace(stdout.String())
-
-			log.Println(" - FAILED")
-			log.Fatalf("Test failed for file: %s (%s)\n", file, out)
+			log.Fatalf("Failed to read %s: %v", file, err)
 		}
 
-		// Decode the captured stdout output as a PNG image
-		img, err := png.Decode(&stdout)
+		defer in.Close()
+
+		img, err := ReadImage(in)
+		if err != nil {
+			log.Fatalf("Failed to decode %s: %v", file, err)
+		}
+
+		before := img.Bounds()
+
+		var result bytes.Buffer
+
+		err = WriteImage(&result, img, "png")
+		if err != nil {
+			log.Fatalf("Failed to encode png image: %v", err)
+		}
+
+		img, err = png.Decode(&result)
 		if err != nil {
 			log.Println(" - FAILED")
 			log.Fatalf("Failed to decode PNG image: %v\n", err)
 		}
 
-		if img == nil {
+		after := img.Bounds()
+
+		if before.Max.X != after.Max.X || before.Max.Y != after.Max.Y {
 			log.Println(" - FAILED")
-			log.Fatalf("No image data returned for file: %s\n", file)
+			log.Fatalf("Invalid image (%dx%d != %dx%d) for file: %s\n", before.Max.X, before.Max.Y, after.Max.X, after.Max.Y, file)
 		}
 
 		log.Println(" - PASSED")
diff --git a/flags.go b/flags.go
deleted file mode 100644
index bfbf545..0000000
--- a/flags.go
+++ /dev/null
@@ -1,187 +0,0 @@
-package main
-
-import (
-	"os"
-	"strconv"
-	"strings"
-)
-
-type Argument struct {
-	IsNil bool
-	Name  string
-	Value string
-}
-
-type Arguments struct {
-	Arguments map[string]Argument
-}
-
-var (
-	arguments Arguments
-)
-
-// I don't like golang flags package
-func init() {
-	arguments = Arguments{
-		Arguments: make(map[string]Argument),
-	}
-
-	var (
-		arg   string
-		val   string
-		index int
-
-		current Argument
-	)
-
-	for i := 1; i < len(os.Args); i++ {
-		arg = os.Args[i]
-
-		if arg[0] == '-' && len(arg) > 1 {
-			if arg[1] == '-' {
-				index = strings.Index(arg[2:], "=")
-
-				if index >= 0 {
-					val = ""
-
-					if index+1 < len(arg) {
-						val = arg[2+index+1:]
-					}
-
-					arguments.Set(Argument{
-						Name:  arg[2 : 2+index],
-						Value: val,
-					})
-				} else {
-					arguments.Set(Argument{
-						Name: arg[2:],
-					})
-				}
-
-				current = Argument{}
-			} else {
-				current = Argument{
-					Name: arg[1:],
-				}
-			}
-		} else {
-			current.Value = arg
-
-			arguments.Set(current)
-
-			current = Argument{}
-		}
-	}
-
-	if current.Name != "" {
-		arguments.Set(current)
-	}
-}
-
-func (a *Arguments) Set(arg Argument) {
-	a.Arguments[arg.Name] = arg
-}
-
-func (a *Arguments) Get(short, long string) Argument {
-	arg, ok := a.Arguments[short]
-
-	if !ok && long != short {
-		arg, ok = a.Arguments[long]
-	}
-
-	if !ok {
-		return Argument{
-			IsNil: true,
-			Name:  long,
-		}
-	}
-
-	return arg
-}
-
-func (a *Arguments) GetString(short, long string) string {
-	return a.Get(short, long).String()
-}
-
-func (a *Arguments) GetBool(short, long string, def bool) bool {
-	return a.Get(short, long).Bool(def)
-}
-
-func (a *Arguments) GetInt64(short, long string, def, min, max int64) int64 {
-	return a.Get(short, long).Int64(def, min, max)
-}
-
-func (a *Arguments) GetUint64(short, long string, def, min, max uint64) uint64 {
-	return a.Get(short, long).Uint64(def, min, max)
-}
-
-func (a *Arguments) GetFloat64(short, long string, def, min, max float64) float64 {
-	return a.Get(short, long).Float64(def, min, max)
-}
-
-func (a Argument) String() string {
-	return a.Value
-}
-
-func (a Argument) Bool(def bool) bool {
-	if a.IsNil {
-		return def
-	}
-
-	if a.Value == "false" || a.Value == "0" {
-		return false
-	}
-
-	return true
-}
-
-func (a Argument) Int64(def, min, max int64) int64 {
-	if a.IsNil {
-		return def
-	}
-
-	i, err := strconv.ParseInt(a.Value, 10, 64)
-	if err != nil {
-		return def
-	}
-
-	return minmax(i, min, max)
-}
-
-func (a Argument) Uint64(def, min, max uint64) uint64 {
-	if a.IsNil {
-		return def
-	}
-
-	i, err := strconv.ParseUint(a.Value, 10, 64)
-	if err != nil {
-		return def
-	}
-
-	return minmax(i, min, max)
-}
-
-func (a Argument) Float64(def, min, max float64) float64 {
-	if a.IsNil {
-		return def
-	}
-
-	i, err := strconv.ParseFloat(a.Value, 64)
-	if err != nil {
-		return def
-	}
-
-	return minmax(i, min, max)
-}
-
-func minmax[T int64 | uint64 | float64](val, min, max T) T {
-	if min != 0 && val < min {
-		return min
-	}
-
-	if max != 0 && val > max {
-		return max
-	}
-
-	return val
-}
diff --git a/format.go b/format.go
index 21fce30..654bb23 100644
--- a/format.go
+++ b/format.go
@@ -7,11 +7,10 @@ import (
 	"image/jpeg"
 	"image/png"
 	"io"
-	"os"
 	"path/filepath"
 	"strings"
 
-	"github.com/biessek/golang-ico"
+	ico "github.com/biessek/golang-ico"
 	"github.com/gen2brain/avif"
 	"github.com/gen2brain/heic"
 	"github.com/gen2brain/jpegxl"
@@ -22,35 +21,35 @@ import (
 
 var (
 	OutputFormats = []string{
-		"jpeg",
-		"png",
-		"webp",
-		"gif",
-		"bmp",
-		"tiff",
 		"avif",
-		"jxl",
+		"bmp",
+		"gif",
 		"ico",
+		"jpeg",
+		"jxl",
+		"png",
+		"tiff",
+		"webp",
 	}
 
 	InputFormats = []string{
-		"jpeg",
-		"png",
-		"webp",
-		"gif",
-		"bmp",
-		"tiff",
 		"avif",
-		"jxl",
-		"ico",
+		"bmp",
+		"gif",
 		"heic",
 		"heif",
+		"ico",
+		"jpeg",
+		"jxl",
+		"png",
+		"tiff",
+		"webp",
 	}
 )
 
 type Decoder func(io.Reader) (image.Image, error)
 
-func GetDecoderFromContent(in *os.File) (Decoder, error) {
+func GetDecoderFromContent(in io.ReadSeeker) (Decoder, error) {
 	buffer := make([]byte, 128)
 
 	_, err := in.Read(buffer)
@@ -139,31 +138,31 @@ func IsJpegXL(buffer []byte) bool {
 	return len(buffer) > 12 && string(buffer[:4]) == "JXL "
 }
 
-func OutputFormatFromPath(path string) string {
+func GetFormatFromPath(path string) string {
 	ext := strings.ToLower(filepath.Ext(path))
 
 	switch ext {
 	case ".webp", ".riff":
 		return "webp"
-	case ".jpg", ".jpeg":
+	case ".jpg", ".jpeg", ".jpe", ".jif", ".jfif":
 		return "jpeg"
 	case ".png":
 		return "png"
-	case ".gif":
+	case ".gif", ".giff":
 		return "gif"
-	case ".bmp":
+	case ".bmp", ".dib", ".rle":
 		return "bmp"
 	case ".tiff", ".tif":
 		return "tiff"
 	case ".avif", ".avifs":
 		return "avif"
-	case ".jxl":
+	case ".jxl", ".jxls":
 		return "jxl"
 	case ".ico":
 		return "ico"
 	}
 
-	return "webp"
+	return ""
 }
 
 func IsValidOutputFormat(format string) bool {
diff --git a/go.mod b/go.mod
index 821dd33..ee20998 100644
--- a/go.mod
+++ b/go.mod
@@ -1,9 +1,10 @@
 module ffwebp
 
-go 1.23.1
+go 1.23.4
 
 require (
 	github.com/biessek/golang-ico v0.0.0-20180326222316-d348d9ea4670
+	github.com/coalaura/arguments v1.5.2
 	github.com/gen2brain/avif v0.3.2
 	github.com/gen2brain/heic v0.3.1
 	github.com/gen2brain/jpegxl v0.3.1
diff --git a/go.sum b/go.sum
index 1ab44a6..267fd29 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,11 @@
 github.com/biessek/golang-ico v0.0.0-20180326222316-d348d9ea4670 h1:FQPKKjDhzG0T4ew6dm6MGrXb4PRAi8ZmTuYuxcF62BM=
 github.com/biessek/golang-ico v0.0.0-20180326222316-d348d9ea4670/go.mod h1:iRWAFbKXMMkVQyxZ1PfGlkBr1TjATx1zy2MRprV7A3Q=
+github.com/coalaura/arguments v1.5.0 h1:apdZXxINepy8qCHYKJYEnLHvV6VbYgsIMPbZCWZAPQY=
+github.com/coalaura/arguments v1.5.0/go.mod h1:F5cdI+Gn1qi5K6qqvAdxdTD2TXkny+gTKU0o6NN1MlU=
+github.com/coalaura/arguments v1.5.1 h1:Gc7uODI3WlcVxmQpxoUQF7Y2j3EMDpSlVqhmGMtLC8Q=
+github.com/coalaura/arguments v1.5.1/go.mod h1:F5cdI+Gn1qi5K6qqvAdxdTD2TXkny+gTKU0o6NN1MlU=
+github.com/coalaura/arguments v1.5.2 h1:hRLKo6XmAzCDOS/unCUVAIYl3WU/i6QX59nBh0T31cw=
+github.com/coalaura/arguments v1.5.2/go.mod h1:F5cdI+Gn1qi5K6qqvAdxdTD2TXkny+gTKU0o6NN1MlU=
 github.com/ebitengine/purego v0.7.1 h1:6/55d26lG3o9VCZX8lping+bZcmShseiqlh2bnUDiPA=
 github.com/ebitengine/purego v0.7.1/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
 github.com/gen2brain/avif v0.3.2 h1:XUR0CBl5n4ISFJE8/pc1RMEKt5KUVoW8InctN+M7+DQ=
diff --git a/help.go b/help.go
index 794c510..2a3ee7f 100644
--- a/help.go
+++ b/help.go
@@ -3,46 +3,63 @@ package main
 import (
 	"fmt"
 	"os"
-	"sort"
-	"strings"
+
+	"github.com/coalaura/arguments"
 )
 
 func help() {
-	if !arguments.GetBool("h", "help", false) {
+	if !opts.Help {
 		return
 	}
 
-	info("  __  __              _")
-	info(" / _|/ _|            | |")
-	info("| |_| |___      _____| |__  _ __")
-	info("|  _|  _\\ \\ /\\ / / _ \\ '_ \\| '_ \\")
-	info("| | | |  \\ V  V /  __/ |_) | |_) |")
-	info("|_| |_|   \\_/\\_/ \\___|_.__/| .__/")
-	info("                           | |")
-	info("                    %s |_|", Version)
+	println("  __  __              _")
+	println(" / _|/ _|            | |")
+	println("| |_| |___      _____| |__  _ __")
+	println("|  _|  _\\ \\ /\\ / / _ \\ '_ \\| '_ \\")
+	println("| | | |  \\ V  V /  __/ |_) | |_) |")
+	println("|_| |_|   \\_/\\_/ \\___|_.__/| .__/")
+	println("                           | |")
+	fmt.Printf("                    %s |_|\n", Version)
 
-	info("\nffwebp -i <input> [output] [options]")
+	println("\nffwebp [options] <input> [output]\n")
 
-	var max int
+	arguments.ShowHelp(true)
 
-	for name := range options {
-		if len(name) > max {
-			max = len(name)
-		}
-	}
+	b := arguments.NewBuilder(true)
 
-	var formatted []string
+	b.WriteRune('\n')
+	b.Mute()
+	b.WriteString(" - ")
+	b.Name()
+	b.WriteString("Input formats")
+	b.Mute()
+	b.WriteString(":  ")
+	values(b, InputFormats)
 
-	for name, help := range options {
-		formatted = append(formatted, fmt.Sprintf(" - %-*s: %s", max, name, help))
-	}
+	b.WriteRune('\n')
+	b.Mute()
+	b.WriteString(" - ")
+	b.Name()
+	b.WriteString("Output formats")
+	b.Mute()
+	b.WriteString(": ")
+	values(b, OutputFormats)
 
-	sort.Strings(formatted)
-
-	info(strings.Join(formatted, "\n"))
-
-	info("\nInput formats:  %s", strings.Join(InputFormats, ", "))
-	info("Output formats: %s", strings.Join(OutputFormats, ", "))
+	println(b.String())
 
 	os.Exit(0)
 }
+
+func values(b *arguments.Builder, v []string) {
+	for i, value := range v {
+		if i > 0 {
+			b.Mute()
+			b.WriteString(", ")
+		}
+
+		b.Value()
+		b.WriteString(value)
+	}
+
+	b.Reset()
+}
diff --git a/image.go b/image.go
index 664a656..b4a26c0 100644
--- a/image.go
+++ b/image.go
@@ -5,10 +5,9 @@ import (
 	"image"
 	"image/gif"
 	"image/jpeg"
-	"image/png"
-	"os"
+	"io"
 
-	"github.com/biessek/golang-ico"
+	ico "github.com/biessek/golang-ico"
 	"github.com/gen2brain/avif"
 	"github.com/gen2brain/jpegxl"
 	"github.com/gen2brain/webp"
@@ -16,23 +15,7 @@ import (
 	"golang.org/x/image/tiff"
 )
 
-var (
-	options = map[string]string{
-		"c / colors":      "Number of colors (1-256) (gif)",
-		"e / effort":      "Encoder effort level (0-10) (jxl)",
-		"f / format":      "Output format (avif, bmp, gif, jpeg, jxl, png, tiff, webp)",
-		"h / help":        "Show this help page",
-		"l / lossless":    "Use lossless compression (webp)",
-		"m / method":      "Encoder method (0=fast, 6=slower-better) (webp)",
-		"r / ratio":       "YCbCr subsample-ratio (0=444, 1=422, 2=420, 3=440, 4=411, 5=410) (avif)",
-		"s / silent":      "Do not print any output",
-		"q / quality":     "Set quality (0-100) (avif, jpeg, jxl, webp)",
-		"x / exact":       "Preserve RGB values in transparent area (webp)",
-		"z / compression": "Compression type (0=uncompressed, 1=deflate, 2=lzw, 3=ccittgroup3, 4=ccittgroup4) (tiff)",
-	}
-)
-
-func ReadImage(input *os.File) (image.Image, error) {
+func ReadImage(input io.ReadSeeker) (image.Image, error) {
 	decoder, err := GetDecoderFromContent(input)
 	if err != nil {
 		return nil, err
@@ -41,7 +24,7 @@ func ReadImage(input *os.File) (image.Image, error) {
 	return decoder(input)
 }
 
-func WriteImage(output *os.File, img image.Image, format string) error {
+func WriteImage(output io.Writer, img image.Image, format string) error {
 	switch format {
 	case "webp":
 		options := GetWebPOptions()
@@ -56,7 +39,11 @@ func WriteImage(output *os.File, img image.Image, format string) error {
 
 		return jpeg.Encode(output, img, options)
 	case "png":
-		return png.Encode(output, img)
+		encoder := GetPNGOptions()
+
+		LogPNGOptions(encoder)
+
+		return encoder.Encode(output, img)
 	case "gif":
 		options := GetGifOptions()
 
diff --git a/log.go b/log.go
index e8d1109..0cf8d1f 100644
--- a/log.go
+++ b/log.go
@@ -14,11 +14,13 @@ func info(fm string, args ...interface{}) {
 		return
 	}
 
-	fmt.Printf(fm+"\n", args...)
+	fmt.Printf(fm, args...)
+	fmt.Println()
 }
 
-func fatalf(code int, fm string, args ...interface{}) {
-	fmt.Printf("ERROR: "+fm+"\n", args...)
+func fatalf(fm string, args ...interface{}) {
+	fmt.Printf("ERROR: "+fm, args...)
+	fmt.Println()
 
-	os.Exit(code)
+	os.Exit(1)
 }
diff --git a/main.go b/main.go
index 481cdac..650fca1 100644
--- a/main.go
+++ b/main.go
@@ -5,77 +5,46 @@ import (
 )
 
 func main() {
-	help()
+	parse()
 
-	silent = arguments.GetBool("s", "silent", false)
+	info("Reading input image...")
 
-	// Read input file
-	input := arguments.GetString("i", "input")
-
-	var in *os.File
-
-	if input == "" {
-		in = os.Stdin
-	} else {
-		var err error
-
-		in, err = os.OpenFile(input, os.O_RDONLY, 0)
-		if err != nil {
-			fatalf(1, "Failed to open input file: %s", err)
-		}
-	}
-
-	// Read image
-	if in == os.Stdin {
-		info("Decoding input from stdin...")
-	} else {
-		info("Decoding input image...")
-	}
-
-	img, err := ReadImage(in)
+	in, err := os.OpenFile(opts.Input, os.O_RDONLY, 0)
 	if err != nil {
-		fatalf(4, "Failed to read image: %s", err)
+		fatalf("Failed to open input file: %s", err)
 	}
 
-	// Read output format
-	format := arguments.GetString("f", "format")
-
-	// Read output file
-	output := arguments.GetString("", "")
+	defer in.Close()
 
 	var out *os.File
 
-	if output == "" {
-		if format == "" {
-			format = "webp"
-		}
+	if opts.Output == "" {
+		opts.Silent = true
 
 		out = os.Stdout
-		silent = true
 	} else {
-		var err error
-
-		if format == "" {
-			format = OutputFormatFromPath(output)
-		}
-
-		out, err = os.OpenFile(output, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
+		out, err = os.OpenFile(opts.Output, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
 		if err != nil {
-			fatalf(2, "Failed to open output file: %s", err)
+			fatalf("Failed to open output file: %s", err)
 		}
+
+		defer out.Close()
 	}
 
-	if !IsValidOutputFormat(format) {
-		fatalf(3, "Invalid output format: %s", format)
+	info("Decoding input image...")
+
+	img, err := ReadImage(in)
+	if err != nil {
+		fatalf("Failed to read image: %s", err)
 	}
 
-	info("Using output format: %s", format)
+	info("Using output format: %s", opts.Format)
 
 	// Write image
 	info("Encoding output image...")
 
-	err = WriteImage(out, img, format)
+	err = WriteImage(out, img, opts.Format)
 	if err != nil {
-		fatalf(5, "Failed to write image: %s", err)
+		fatalf("Failed to write image: %s", err)
 	}
 }
diff --git a/options.go b/options.go
index 24860c9..22b1a4c 100644
--- a/options.go
+++ b/options.go
@@ -4,19 +4,160 @@ import (
 	"image"
 	"image/gif"
 	"image/jpeg"
+	"image/png"
 
+	"github.com/coalaura/arguments"
 	"github.com/gen2brain/avif"
 	"github.com/gen2brain/jpegxl"
 	"github.com/gen2brain/webp"
 	"golang.org/x/image/tiff"
 )
 
+type Options struct {
+	Help   bool
+	Input  string
+	Output string
+
+	Silent      bool
+	NumColors   int
+	Effort      int
+	Format      string
+	Lossless    bool
+	Method      int
+	Ratio       int
+	Quality     int
+	Exact       bool
+	Compression int
+	Level       int
+	Speed       int
+}
+
+var opts = Options{
+	Help:   false,
+	Input:  "",
+	Output: "",
+
+	Silent:      false,
+	NumColors:   256,
+	Effort:      10,
+	Format:      "",
+	Lossless:    false,
+	Method:      6,
+	Ratio:       0,
+	Quality:     90,
+	Exact:       false,
+	Compression: 2,
+	Level:       2,
+	Speed:       0,
+}
+
+func parse() {
+	// General options
+	arguments.Register("help", 'h', &opts.Help).WithHelp("Show this help message")
+	arguments.Register("silent", 's', &opts.Silent).WithHelp("Do not print any output")
+	arguments.Register("format", 'f', &opts.Format).WithHelp("Output format (avif, bmp, gif, jpeg, jxl, png, tiff, webp, ico)")
+
+	// Common image options
+	arguments.Register("quality", 'q', &opts.Quality).WithHelp("[avif|jpeg|jxl|webp] Quality level (1-100)")
+
+	// AVIF
+	arguments.Register("ratio", 'r', &opts.Ratio).WithHelp("[avif] YCbCr subsample-ratio (0=444, 1=422, 2=420, 3=440, 4=411, 5=410)")
+	arguments.Register("speed", 'p', &opts.Speed).WithHelp("[avif] Encoder speed level (0=fast, 10=slower-better)")
+
+	// GIF
+	arguments.Register("colors", 'c', &opts.NumColors).WithHelp("[gif] Number of colors to use (1-256)")
+
+	// JXL
+	arguments.Register("effort", 'e', &opts.Effort).WithHelp("[jxl] Encoder effort level (0=fast, 10=slower-better)")
+
+	// PNG
+	arguments.Register("level", 'g', &opts.Level).WithHelp("[png] Compression level (0=no-compression, 1=best-speed, 2=best-compression)")
+
+	// TIFF
+	arguments.Register("compression", 't', &opts.Compression).WithHelp("[tiff] Compression type (0=uncompressed, 1=deflate, 2=lzw, 3=ccittgroup3, 4=ccittgroup4)")
+
+	// WebP
+	arguments.Register("exact", 'x', &opts.Exact).WithHelp("[webp] Preserve RGB values in transparent area")
+	arguments.Register("lossless", 'l', &opts.Lossless).WithHelp("[webp] Use lossless compression")
+	arguments.Register("method", 'm', &opts.Method).WithHelp("[webp] Encoder method (0=fast, 6=slower-better)")
+
+	arguments.Parse()
+
+	help()
+
+	if len(arguments.Args) < 1 {
+		fatalf("Missing input file")
+	}
+
+	opts.Input = arguments.Args[0]
+
+	if len(arguments.Args) > 1 {
+		opts.Output = arguments.Args[1]
+	}
+
+	if opts.Format != "" && !IsValidOutputFormat(opts.Format) {
+		fatalf("Invalid output format: %s", opts.Format)
+	}
+
+	// Resolve format from output file
+	if opts.Format == "" && opts.Output != "" {
+		opts.Format = GetFormatFromPath(opts.Output)
+	}
+
+	// Otherwise resolve format from input file
+	if opts.Format == "" {
+		opts.Format = GetFormatFromPath(opts.Input)
+	}
+
+	// Or default to webp
+	if opts.Format == "" {
+		opts.Format = "webp"
+	} else if opts.Format == "jpg" {
+		opts.Format = "jpeg"
+	}
+
+	// NumColors must be between 1 and 256
+	if opts.NumColors < 1 || opts.NumColors > 256 {
+		opts.NumColors = 256
+	}
+
+	// Effort must be between 0 and 10
+	if opts.Effort < 0 || opts.Effort > 10 {
+		opts.Effort = 10
+	}
+
+	// Method must be between 0 and 6
+	if opts.Method < 0 || opts.Method > 6 {
+		opts.Method = 6
+	}
+
+	// Quality must be between 1 and 100
+	if opts.Quality < 1 || opts.Quality > 100 {
+		opts.Quality = 90
+	}
+
+	// Ratio must be between 0 and 5
+	if opts.Ratio < 0 || opts.Ratio > 5 {
+		opts.Ratio = 0
+	}
+
+	// Compression must be between 0 and 4
+	if opts.Compression < 0 || opts.Compression > 4 {
+		opts.Compression = 2
+	}
+
+	// Level must be between 0 and 2
+	if opts.Level < 0 || opts.Level > 2 {
+		opts.Level = 2
+	}
+}
+
 func GetWebPOptions() webp.Options {
 	return webp.Options{
-		Lossless: arguments.GetBool("l", "lossless", false),
-		Quality:  int(arguments.GetUint64("q", "quality", 100, 0, 100)),
-		Method:   int(arguments.GetUint64("m", "method", 4, 0, 6)),
-		Exact:    arguments.GetBool("x", "exact", false),
+		Lossless: opts.Lossless,
+		Quality:  opts.Quality,
+		Method:   opts.Method,
+		Exact:    opts.Exact,
 	}
 }
 
@@ -30,7 +171,7 @@ func LogWebPOptions(options webp.Options) {
 
 func GetJpegOptions() *jpeg.Options {
 	return &jpeg.Options{
-		Quality: int(arguments.GetUint64("q", "quality", 100, 0, 100)),
+		Quality: opts.Quality,
 	}
 }
 
@@ -39,9 +180,20 @@ func LogJpegOptions(options *jpeg.Options) {
 	info(" - quality: %v", options.Quality)
 }
 
+func GetPNGOptions() *png.Encoder {
+	return &png.Encoder{
+		CompressionLevel: GetPNGCompressionLevel(),
+	}
+}
+
+func LogPNGOptions(encoder *png.Encoder) {
+	info("Using output options:")
+	info(" - level: %s", PNGCompressionLevelToString(encoder.CompressionLevel))
+}
+
 func GetGifOptions() *gif.Options {
 	return &gif.Options{
-		NumColors: int(arguments.GetUint64("c", "colors", 256, 0, 256)),
+		NumColors: opts.NumColors,
 	}
 }
 
@@ -63,9 +215,9 @@ func LogTiffOptions(options *tiff.Options) {
 
 func GetAvifOptions() avif.Options {
 	return avif.Options{
-		Quality:           int(arguments.GetUint64("q", "quality", 100, 0, 100)),
-		QualityAlpha:      int(arguments.GetUint64("qa", "quality-alpha", 100, 0, 100)),
-		Speed:             int(arguments.GetUint64("s", "speed", 6, 0, 10)),
+		Quality:           opts.Quality,
+		QualityAlpha:      opts.Quality,
+		Speed:             opts.Speed,
 		ChromaSubsampling: GetAvifYCbCrSubsampleRatio(),
 	}
 }
@@ -80,8 +232,8 @@ func LogAvifOptions(options avif.Options) {
 
 func GetJxlOptions() jpegxl.Options {
 	return jpegxl.Options{
-		Quality: int(arguments.GetUint64("q", "quality", 100, 0, 100)),
-		Effort:  int(arguments.GetUint64("e", "effort", 7, 0, 10)),
+		Quality: opts.Quality,
+		Effort:  opts.Effort,
 	}
 }
 
@@ -92,9 +244,7 @@ func LogJxlOptions(options jpegxl.Options) {
 }
 
 func GetTiffCompressionType() tiff.CompressionType {
-	compression := arguments.GetUint64("z", "compression", 1, 0, 4)
-
-	switch compression {
+	switch opts.Compression {
 	case 0:
 		return tiff.Uncompressed
 	case 1:
@@ -128,9 +278,7 @@ func TiffCompressionTypeToString(compression tiff.CompressionType) string {
 }
 
 func GetAvifYCbCrSubsampleRatio() image.YCbCrSubsampleRatio {
-	sampleRatio := arguments.GetUint64("r", "sample-ratio", 0, 0, 5)
-
-	switch sampleRatio {
+	switch opts.Ratio {
 	case 0:
 		return image.YCbCrSubsampleRatio444
 	case 1:
@@ -147,3 +295,29 @@ func GetAvifYCbCrSubsampleRatio() image.YCbCrSubsampleRatio {
 
 	return image.YCbCrSubsampleRatio444
 }
+
+func GetPNGCompressionLevel() png.CompressionLevel {
+	switch opts.Level {
+	case 0:
+		return png.NoCompression
+	case 1:
+		return png.BestSpeed
+	case 2:
+		return png.BestCompression
+	}
+
+	return png.BestCompression
+}
+
+func PNGCompressionLevelToString(level png.CompressionLevel) string {
+	switch level {
+	case png.NoCompression:
+		return "no-compression"
+	case png.BestSpeed:
+		return "best-speed"
+	case png.BestCompression:
+		return "best-compression"
+	default:
+		return "unknown"
+	}
+}
diff --git a/version.go b/version.go
index 15baba7..c3205e5 100644
--- a/version.go
+++ b/version.go
@@ -1,3 +1,3 @@
 package main
 
-const Version = "development"
+const Version = "   dev"