Merge pull request #13 from celogeek/compute-aspect-ratio

Compute aspect ratio

internal/converter/converter.go

@@ -84,6 +84,12 @@ func (c *Converter) AddIntParam(p *int, name string, value int, usage string) {
 	c.order = append(c.order, converterOrderName{value: name})
 }
 
+// Add an float parameter
+func (c *Converter) AddFloatParam(p *float64, name string, value float64, usage string) {
+	c.Cmd.Float64Var(p, name, value, usage)
+	c.order = append(c.order, converterOrderName{value: name})
+}
+
 // Add a boolean parameter
 func (c *Converter) AddBoolParam(p *bool, name string, value bool, usage string) {
 	c.Cmd.BoolVar(p, name, value, usage)
@@ -121,6 +127,7 @@ func (c *Converter) InitParse() {
 	c.AddStringParam(&c.Options.BackgroundColor, "background-color", c.Options.BackgroundColor, "Background color in hexa format RGB. Black=000, White=FFF, Light Gray=DDD, Dark Gray=777")
 	c.AddBoolParam(&c.Options.NoResize, "noresize", c.Options.NoResize, "Do not reduce image size if exceed device size")
 	c.AddStringParam(&c.Options.Format, "format", c.Options.Format, "Format of output images: jpeg (lossy), png (lossless)")
+	c.AddFloatParam(&c.Options.AspectRatio, "aspect-ratio", c.Options.AspectRatio, "Aspect ratio (height/width) of the output\n -1 = same as device\n  0 = same as source\n1.6 = amazon advice for kindle")
 
 	c.AddSection("Default config")
 	c.AddBoolParam(&c.Options.Show, "show", false, "Show your default parameters")
@@ -351,6 +358,11 @@ func (c *Converter) Validate() error {
 		return errors.New("format should be jpeg or png")
 	}
 
+	// Aspect Ratio
+	if c.Options.AspectRatio < 0 && c.Options.AspectRatio != -1 {
+		return errors.New("aspect ratio should be: -1, 0, > 0")
+	}
+
 	return nil
 }
 

internal/converter/options/converter_options.go

@@ -21,28 +21,29 @@ type Options struct {
 	Title  string `yaml:"-"`
 
 	// Config
-	Profile                    string `yaml:"profile"`
+	Profile                    string  `yaml:"profile"`
-	Quality                    int    `yaml:"quality"`
+	Quality                    int     `yaml:"quality"`
-	Grayscale                  bool   `yaml:"grayscale"`
+	Grayscale                  bool    `yaml:"grayscale"`
-	Crop                       bool   `yaml:"crop"`
+	Crop                       bool    `yaml:"crop"`
-	CropRatioLeft              int    `yaml:"crop_ratio_left"`
+	CropRatioLeft              int     `yaml:"crop_ratio_left"`
-	CropRatioUp                int    `yaml:"crop_ratio_up"`
+	CropRatioUp                int     `yaml:"crop_ratio_up"`
-	CropRatioRight             int    `yaml:"crop_ratio_right"`
+	CropRatioRight             int     `yaml:"crop_ratio_right"`
-	CropRatioBottom            int    `yaml:"crop_ratio_bottom"`
+	CropRatioBottom            int     `yaml:"crop_ratio_bottom"`
-	Brightness                 int    `yaml:"brightness"`
+	Brightness                 int     `yaml:"brightness"`
-	Contrast                   int    `yaml:"contrast"`
+	Contrast                   int     `yaml:"contrast"`
-	AutoRotate                 bool   `yaml:"auto_rotate"`
+	AutoRotate                 bool    `yaml:"auto_rotate"`
-	AutoSplitDoublePage        bool   `yaml:"auto_split_double_page"`
+	AutoSplitDoublePage        bool    `yaml:"auto_split_double_page"`
-	NoBlankImage               bool   `yaml:"no_blank_image"`
+	NoBlankImage               bool    `yaml:"no_blank_image"`
-	Manga                      bool   `yaml:"manga"`
+	Manga                      bool    `yaml:"manga"`
-	HasCover                   bool   `yaml:"has_cover"`
+	HasCover                   bool    `yaml:"has_cover"`
-	LimitMb                    int    `yaml:"limit_mb"`
+	LimitMb                    int     `yaml:"limit_mb"`
-	StripFirstDirectoryFromToc bool   `yaml:"strip_first_directory_from_toc"`
+	StripFirstDirectoryFromToc bool    `yaml:"strip_first_directory_from_toc"`
-	SortPathMode               int    `yaml:"sort_path_mode"`
+	SortPathMode               int     `yaml:"sort_path_mode"`
-	ForegroundColor            string `yaml:"foreground_color"`
+	ForegroundColor            string  `yaml:"foreground_color"`
-	BackgroundColor            string `yaml:"background_color"`
+	BackgroundColor            string  `yaml:"background_color"`
-	NoResize                   bool   `yaml:"noresize"`
+	NoResize                   bool    `yaml:"noresize"`
-	Format                     string `yaml:"format"`
+	Format                     string  `yaml:"format"`
+	AspectRatio                float64 `yaml:"aspect_ratio"`
 
 	// Default Config
 	Show  bool `yaml:"-"`
@@ -94,6 +95,7 @@ func New() *Options {
 		BackgroundColor:            "FFF",
 		NoResize:                   false,
 		Format:                     "jpeg",
+		AspectRatio:                0,
 		profiles:                   profiles.New(),
 	}
 }
@@ -145,7 +147,7 @@ func (o *Options) LoadConfig() error {
 
 // Get current settings for fields that can be saved
 func (o *Options) ShowConfig() string {
-	var profileDesc, viewDesc string
+	var profileDesc string
 	profile := o.GetProfile()
 	if profile != nil {
 		profileDesc = fmt.Sprintf(
@@ -155,13 +157,6 @@ func (o *Options) ShowConfig() string {
 			profile.Width,
 			profile.Height,
 		)
-
-		perfectWidth, perfectHeight := profile.PerfectDim()
-		viewDesc = fmt.Sprintf(
-			"%dx%d",
-			perfectWidth,
-			perfectHeight,
-		)
 	}
 
 	sortpathmode := ""
@@ -174,6 +169,13 @@ func (o *Options) ShowConfig() string {
 		sortpathmode = "path=alphanum, file=alphanum"
 	}
 
+	aspectRatio := "auto"
+	if o.AspectRatio > 0 {
+		aspectRatio = fmt.Sprintf("1:%.02f", o.AspectRatio)
+	} else if o.AspectRatio < 0 {
+		aspectRatio = fmt.Sprintf("1:%0.2f (device)", float64(profile.Height)/float64(profile.Width))
+	}
+
 	var b strings.Builder
 	for _, v := range []struct {
 		Key       string
@@ -181,8 +183,6 @@ func (o *Options) ShowConfig() string {
 		Condition bool
 	}{
 		{"Profile", profileDesc, true},
-		{"ViewRatio", fmt.Sprintf("1:%s", strings.TrimRight(fmt.Sprintf("%f", profiles.PerfectRatio), "0")), true},
-		{"View", viewDesc, true},
 		{"Format", o.Format, true},
 		{"Quality", o.Quality, o.Format == "jpeg"},
 		{"Grayscale", o.Grayscale, true},
@@ -201,6 +201,7 @@ func (o *Options) ShowConfig() string {
 		{"Foreground Color", fmt.Sprintf("#%s", o.ForegroundColor), true},
 		{"Background Color", fmt.Sprintf("#%s", o.BackgroundColor), true},
 		{"Resize", !o.NoResize, true},
+		{"Aspect Ratio", aspectRatio, true},
 	} {
 		if v.Condition {
 			b.WriteString(fmt.Sprintf("\n    %-26s: %v", v.Key, v.Value))

internal/converter/profiles/converter_profiles.go

@@ -15,21 +15,6 @@ type Profile struct {
 	Height      int
 }
 
-// Recommended ratio of image for perfect rendering Portrait or Landscape.
-const PerfectRatio = 1.6
-
-// Compute best dimension based on device size
-func (p Profile) PerfectDim() (int, int) {
-	width, height := float64(p.Width), float64(p.Height)
-	perfectWidth, perfectHeight := height/PerfectRatio, width*PerfectRatio
-	if perfectWidth > width {
-		perfectWidth = width
-	} else {
-		perfectHeight = height
-	}
-	return int(perfectWidth), int(perfectHeight)
-}
-
 type Profiles []Profile
 
 // Initialize list of all supported profiles.

internal/epub/epub.go

@@ -6,6 +6,7 @@ package epub
 import (
 	"archive/zip"
 	"fmt"
+	"math"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -193,6 +194,52 @@ func (e *ePub) getTree(images []*epubimage.Image, skip_files bool) string {
 	return c.WriteString("")
 }
 
+func (e *ePub) computeAspectRatio(epubParts []*epubPart) float64 {
+	var (
+		bestAspectRatio      float64
+		bestAspectRatioCount int
+		aspectRatio          = map[float64]int{}
+	)
+
+	trunc := func(v float64) float64 {
+		return float64(math.Round(v*10000)) / 10000
+	}
+
+	for _, p := range epubParts {
+		aspectRatio[trunc(p.Cover.OriginalAspectRatio)]++
+		for _, i := range p.Images {
+			aspectRatio[trunc(i.OriginalAspectRatio)]++
+		}
+	}
+
+	for k, v := range aspectRatio {
+		if v > bestAspectRatioCount {
+			bestAspectRatio, bestAspectRatioCount = k, v
+		}
+	}
+
+	return bestAspectRatio
+}
+
+func (e *ePub) computeViewPort(epubParts []*epubPart) {
+	if e.Image.View.AspectRatio == -1 {
+		return //keep device size
+	}
+
+	// readjusting view port
+	bestAspectRatio := e.Image.View.AspectRatio
+	if bestAspectRatio == 0 {
+		bestAspectRatio = e.computeAspectRatio(epubParts)
+	}
+
+	viewWidth, viewHeight := int(float64(e.Image.View.Height)/bestAspectRatio), int(float64(e.Image.View.Width)*bestAspectRatio)
+	if viewWidth > e.Image.View.Width {
+		e.Image.View.Height = viewHeight
+	} else {
+		e.Image.View.Width = viewWidth
+	}
+}
+
 // create the zip
 func (e *ePub) Write() error {
 	type zipContent struct {
@@ -231,6 +278,7 @@ func (e *ePub) Write() error {
 		Quiet:       e.Quiet,
 	})
 
+	e.computeViewPort(epubParts)
 	for i, part := range epubParts {
 		ext := filepath.Ext(e.Output)
 		suffix := ""

internal/epub/image/epub_image.go

@@ -10,18 +10,19 @@ import (
 )
 
 type Image struct {
-	Id         int
+	Id                  int
-	Part       int
+	Part                int
-	Raw        image.Image
+	Raw                 image.Image
-	Width      int
+	Width               int
-	Height     int
+	Height              int
-	IsCover    bool
+	IsCover             bool
-	IsBlank    bool
+	IsBlank             bool
-	DoublePage bool
+	DoublePage          bool
-	Path       string
+	Path                string
-	Name       string
+	Name                string
-	Position   string
+	Position            string
-	Format     string
+	Format              string
+	OriginalAspectRatio float64
 }
 
 // key name of the blank plage after the image

internal/epub/imageprocessor/epub_image_processor.go

@@ -85,17 +85,18 @@ func (e *EPUBImageProcessor) Load() (images []*epubimage.Image, err error) {
 					}
 
 					img := &epubimage.Image{
-						Id:         input.Id,
+						Id:                  input.Id,
-						Part:       part,
+						Part:                part,
-						Raw:        raw,
+						Raw:                 raw,
-						Width:      dst.Bounds().Dx(),
+						Width:               dst.Bounds().Dx(),
-						Height:     dst.Bounds().Dy(),
+						Height:              dst.Bounds().Dy(),
-						IsCover:    input.Id == 0 && part == 0,
+						IsCover:             input.Id == 0 && part == 0,
-						IsBlank:    dst.Bounds().Dx() == 1 && dst.Bounds().Dy() == 1,
+						IsBlank:             dst.Bounds().Dx() == 1 && dst.Bounds().Dy() == 1,
-						DoublePage: part == 0 && src.Bounds().Dx() > src.Bounds().Dy(),
+						DoublePage:          part == 0 && src.Bounds().Dx() > src.Bounds().Dy(),
-						Path:       input.Path,
+						Path:                input.Path,
-						Name:       input.Name,
+						Name:                input.Name,
-						Format:     e.Image.Format,
+						Format:              e.Image.Format,
+						OriginalAspectRatio: float64(src.Bounds().Dy()) / float64(src.Bounds().Dx()),
 					}
 
 					if err = imgStorage.Add(img.EPUBImgPath(), dst, e.Image.Quality); err != nil {

internal/epub/options/epub_options.go

@@ -16,6 +16,7 @@ type Color struct {
 
 type View struct {
 	Width, Height int
+	AspectRatio   float64
 	Color         Color
 }
 

main.go

@@ -99,7 +99,6 @@ $ go install github.com/celogeek/go-comic-converter/v%d@%s
 	fmt.Fprintln(os.Stderr, cmd.Options)
 
 	profile := cmd.Options.GetProfile()
-	perfectWidth, perfectHeight := profile.PerfectDim()
 
 	if err := epub.New(&epuboptions.Options{
 		Input:                      cmd.Options.Input,
@@ -131,8 +130,9 @@ $ go install github.com/celogeek/go-comic-converter/v%d@%s
 			Manga:               cmd.Options.Manga,
 			HasCover:            cmd.Options.HasCover,
 			View: &epuboptions.View{
-				Width:  perfectWidth,
+				Width:       profile.Width,
-				Height: perfectHeight,
+				Height:      profile.Height,
+				AspectRatio: cmd.Options.AspectRatio,
 				Color: epuboptions.Color{
 					Foreground: cmd.Options.ForegroundColor,
 					Background: cmd.Options.BackgroundColor,