improve crop ratio

internal/converter/converter.go

@@ -98,7 +98,10 @@ func (c *Converter) InitParse() {
 	c.AddStringParam(&c.Options.Profile, "profile", c.Options.Profile, fmt.Sprintf("Profile to use: \n%s", c.Options.AvailableProfiles()))
 	c.AddIntParam(&c.Options.Quality, "quality", c.Options.Quality, "Quality of the image")
 	c.AddBoolParam(&c.Options.Crop, "crop", c.Options.Crop, "Crop images")
-	c.AddIntParam(&c.Options.CropRatio, "crop-ratio", c.Options.CropRatio, "Crop ratio: ratio of pixels allow to be non blank while cutting. 0 mean first non blank stop cutting. 5 may help to remove number.")
+	c.AddIntParam(&c.Options.CropRatioLeft, "crop-ratio-left", c.Options.CropRatioLeft, "Crop ratio left: ratio of pixels allow to be non blank while cutting on the left.")
+	c.AddIntParam(&c.Options.CropRatioUp, "crop-ratio-up", c.Options.CropRatioUp, "Crop ratio up: ratio of pixels allow to be non blank while cutting on the top.")
+	c.AddIntParam(&c.Options.CropRatioRight, "crop-ratio-right", c.Options.CropRatioRight, "Crop ratio right: ratio of pixels allow to be non blank while cutting on the right.")
+	c.AddIntParam(&c.Options.CropRatioBottom, "crop-ratio-bottom", c.Options.CropRatioBottom, "Crop ratio bottom: ratio of pixels allow to be non blank while cutting on the bottom.")
 	c.AddIntParam(&c.Options.Brightness, "brightness", c.Options.Brightness, "Brightness readjustement: between -100 and 100, > 0 lighter, < 0 darker")
 	c.AddIntParam(&c.Options.Contrast, "contrast", c.Options.Contrast, "Contrast readjustement: between -100 and 100, > 0 more contrast, < 0 less contrast")
 	c.AddBoolParam(&c.Options.AutoRotate, "autorotate", c.Options.AutoRotate, "Auto Rotate page when width > height")

internal/converter/options/converter_options.go

@@ -24,7 +24,10 @@ type Options struct {
 	Profile                    string `yaml:"profile"`
 	Quality                    int    `yaml:"quality"`
 	Crop                       bool   `yaml:"crop"`
-	CropRatio                  int    `yaml:"crop_ratio"`
+	CropRatioLeft              int    `yaml:"crop_ratio_left"`
+	CropRatioUp                int    `yaml:"crop_ratio_up"`
+	CropRatioRight             int    `yaml:"crop_ratio_right"`
+	CropRatioBottom            int    `yaml:"crop_ratio_bottom"`
 	Brightness                 int    `yaml:"brightness"`
 	Contrast                   int    `yaml:"contrast"`
 	Auto                       bool   `yaml:"-"`
@@ -60,7 +63,10 @@ func New() *Options {
 		Profile:                    "",
 		Quality:                    85,
 		Crop:                       true,
-		CropRatio:                  5,
+		CropRatioLeft:              1,
+		CropRatioUp:                1,
+		CropRatioRight:             1,
+		CropRatioBottom:            3,
 		Brightness:                 0,
 		Contrast:                   0,
 		AutoRotate:                 false,
@@ -161,7 +167,7 @@ func (o *Options) ShowConfig() string {
     View                      : %s
     Quality                   : %d
     Crop                      : %v
-    CropRatio                 : %d
+    CropRatio                 : %d Left - %d Up - %d Right - %d Bottom
     Brightness                : %d
     Contrast                  : %d
     AutoRotate                : %v
@@ -177,7 +183,7 @@ func (o *Options) ShowConfig() string {
 		viewDesc,
 		o.Quality,
 		o.Crop,
-		o.CropRatio,
+		o.CropRatioLeft, o.CropRatioUp, o.CropRatioRight, o.CropRatioBottom,
 		o.Brightness,
 		o.Contrast,
 		o.AutoRotate,

internal/epub/image/epub_image_options.go

@@ -3,7 +3,10 @@ package epubimage
 // options for image transformation
 type Options struct {
 	Crop                bool
-	CropRatio           int
+	CropRatioLeft       int
+	CropRatioUp         int
+	CropRatioRight      int
+	CropRatioBottom     int
 	ViewWidth           int
 	ViewHeight          int
 	Quality             int

internal/epub/imageprocessing/epub_image_processing.go

@@ -102,7 +102,12 @@ func LoadImages(o *Options) ([]*epubimage.Image, error) {
 				}
 
 				if o.Image.Crop {
-					g := gift.New(gift.Crop(findMarging(src, o.Image.CropRatio)))
+					g := gift.New(gift.Crop(findMarging(src, cutRatioOptions{
+						Left:   o.Image.CropRatioLeft,
+						Up:     o.Image.CropRatioUp,
+						Right:  o.Image.CropRatioRight,
+						Bottom: o.Image.CropRatioBottom,
+					})))
 					newSrc := image.NewNRGBA(g.Bounds(src.Bounds()))
 					g.Draw(newSrc, src)
 					src = newSrc

internal/epub/imageprocessing/epub_image_processing_helpers.go

@@ -25,12 +25,16 @@ func colorIsBlank(c color.Color) bool {
 }
 
 // lookup for margin (blank) around the image
-func findMarging(img image.Image, cutRatio int) image.Rectangle {
+type cutRatioOptions struct {
+	Left, Up, Right, Bottom int
+}
+
+func findMarging(img image.Image, cutRatio cutRatioOptions) image.Rectangle {
 	imgArea := img.Bounds()
 
 LEFT:
 	for x := imgArea.Min.X; x < imgArea.Max.X; x++ {
-		allowNonBlank := imgArea.Dy() * cutRatio / 100
+		allowNonBlank := imgArea.Dy() * cutRatio.Left / 100
 		for y := imgArea.Min.Y; y < imgArea.Max.Y; y++ {
 			if !colorIsBlank(img.At(x, y)) {
 				allowNonBlank--
@@ -44,7 +48,7 @@ LEFT:
 
 UP:
 	for y := imgArea.Min.Y; y < imgArea.Max.Y; y++ {
-		allowNonBlank := imgArea.Dx() * cutRatio / 100
+		allowNonBlank := imgArea.Dx() * cutRatio.Up / 100
 		for x := imgArea.Min.X; x < imgArea.Max.X; x++ {
 			if !colorIsBlank(img.At(x, y)) {
 				allowNonBlank--
@@ -58,7 +62,7 @@ UP:
 
 RIGHT:
 	for x := imgArea.Max.X - 1; x >= imgArea.Min.X; x-- {
-		allowNonBlank := imgArea.Dy() * cutRatio / 100
+		allowNonBlank := imgArea.Dy() * cutRatio.Right / 100
 		for y := imgArea.Min.Y; y < imgArea.Max.Y; y++ {
 			if !colorIsBlank(img.At(x, y)) {
 				allowNonBlank--
@@ -72,7 +76,7 @@ RIGHT:
 
 BOTTOM:
 	for y := imgArea.Max.Y - 1; y >= imgArea.Min.Y; y-- {
-		allowNonBlank := imgArea.Dx() * cutRatio / 100
+		allowNonBlank := imgArea.Dx() * cutRatio.Bottom / 100
 		for x := imgArea.Min.X; x < imgArea.Max.X; x++ {
 			if !colorIsBlank(img.At(x, y)) {
 				allowNonBlank--

main.go

@@ -114,7 +114,10 @@ $ go install github.com/celogeek/go-comic-converter/v%d@%s
 			ViewHeight:          perfectHeight,
 			Quality:             cmd.Options.Quality,
 			Crop:                cmd.Options.Crop,
-			CropRatio:           cmd.Options.CropRatio,
+			CropRatioLeft:       cmd.Options.CropRatioLeft,
+			CropRatioUp:         cmd.Options.CropRatioUp,
+			CropRatioRight:      cmd.Options.CropRatioRight,
+			CropRatioBottom:     cmd.Options.CropRatioBottom,
 			Brightness:          cmd.Options.Brightness,
 			Contrast:            cmd.Options.Contrast,
 			AutoRotate:          cmd.Options.AutoRotate,