Add NoUpscale option

cmd/cbconvert-gui/options.go

@@ -25,6 +25,7 @@ func options() cbconvert.Options {
 	opts.Height = iup.GetHandle("Height").GetInt("VALUE")
 	opts.DPI = dpiValue(iup.GetHandle("DPI").GetAttribute("VALUE"))
 	opts.Fit = iup.GetHandle("Fit").GetAttribute("VALUE") == "ON"
+	opts.NoUpscale = iup.GetHandle("NoUpscale").GetAttribute("VALUE") == "ON"
 	opts.Filter = iup.GetHandle("Filter").GetInt("VALUE") - 1
 	opts.Quality = iup.GetHandle("Quality").GetInt("VALUE")
 	switch opts.Format {

cmd/cbconvert-gui/settings.go

@@ -39,6 +39,7 @@ var settings = []setting{
 	{"NoNonImage", kindBool, "OFF"},
 	{"Combine", kindBool, "OFF"},
 	{"Fit", kindBool, "OFF"},
+	{"NoUpscale", kindBool, "OFF"},
 	{"Lossless", kindBool, "OFF"},
 	{"Grayscale", kindBool, "OFF"},
 	{"OutDir", kindStr, ""},

cmd/cbconvert-gui/widgets.go

@@ -359,6 +359,8 @@ func tabImage() iup.Ihandle {
 			iup.Vbox(
 				iup.Toggle(" Best Fit").SetHandle("Fit").
 					SetAttributes(`TIP="Best fit for required width and height"`),
+				iup.Toggle(" No Upscale").SetHandle("NoUpscale").
+					SetAttribute("TIP", "Do not enlarge images already smaller than the requested size"),
 			),
 			iup.Vbox(
 				iup.Label("Resize Filter:"),

cmd/cbconvert/go.mod

@@ -5,6 +5,7 @@ go 1.26
 require (
 	github.com/gen2brain/cbconvert v1.0.5-0.20260623161611-a5817c3ba5de
 	github.com/schollz/progressbar/v3 v3.19.0
+	golang.org/x/term v0.44.0
 )
 
 require (
@@ -52,7 +53,6 @@ require (
 	golang.org/x/net v0.56.0 // indirect
 	golang.org/x/sync v0.21.0 // indirect
 	golang.org/x/sys v0.46.0 // indirect
-	golang.org/x/term v0.44.0 // indirect
 	golang.org/x/text v0.38.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )

cmd/cbconvert/main.go

@@ -192,6 +192,7 @@ func parseFlags() (cbconvert.Options, []string) {
 	convert.IntVar(&opts.Width, "width", 0, "Image width")
 	convert.IntVar(&opts.Height, "height", 0, "Image height")
 	convert.BoolVar(&opts.Fit, "fit", false, "Best fit for required width and height")
+	convert.BoolVar(&opts.NoUpscale, "no-upscale", false, "Do not upscale images already smaller than the requested width/height")
 	convert.IntVar(&opts.DPI, "dpi", 0, "Document rendering resolution in DPI (PDF, EPUB, etc.), 0 uses the default (300)")
 	convert.StringVar(&opts.Format, "format", "jpeg", "Image format, valid values are jpeg, png, tiff, bmp, webp, avif, jxl")
 	convert.StringVar(&opts.Archive, "archive", "zip", "Archive format, valid values are zip, tar")
@@ -220,6 +221,7 @@ func parseFlags() (cbconvert.Options, []string) {
 	cover.IntVar(&opts.Width, "width", 0, "Image width")
 	cover.IntVar(&opts.Height, "height", 0, "Image height")
 	cover.BoolVar(&opts.Fit, "fit", false, "Best fit for required width and height")
+	cover.BoolVar(&opts.NoUpscale, "no-upscale", false, "Do not upscale images already smaller than the requested width/height")
 	cover.IntVar(&opts.DPI, "dpi", 0, "Document rendering resolution in DPI (PDF, EPUB, etc.), 0 uses the default (300)")
 	cover.StringVar(&opts.Format, "format", "jpeg", "Image format, valid values are jpeg, png, tiff, bmp, webp, avif")
 	cover.IntVar(&opts.Quality, "quality", 75, "Image quality")
@@ -235,6 +237,7 @@ func parseFlags() (cbconvert.Options, []string) {
 	thumbnail.IntVar(&opts.Width, "width", 0, "Image width")
 	thumbnail.IntVar(&opts.Height, "height", 0, "Image height")
 	thumbnail.BoolVar(&opts.Fit, "fit", false, "Best fit for required width and height")
+	thumbnail.BoolVar(&opts.NoUpscale, "no-upscale", false, "Do not upscale images already smaller than the requested width/height")
 	thumbnail.IntVar(&opts.DPI, "dpi", 0, "Document rendering resolution in DPI (PDF, EPUB, etc.), 0 uses the default (300)")
 	thumbnail.IntVar(&opts.Filter, "filter", 2, "0=NearestNeighbor, 1=Box, 2=Linear, 3=MitchellNetravali, 4=CatmullRom, 6=Gaussian, 7=Lanczos")
 	thumbnail.StringVar(&opts.OutDir, "outdir", ".", "Output directory")
@@ -256,7 +259,7 @@ func parseFlags() (cbconvert.Options, []string) {
 		fmt.Fprintf(os.Stderr, "Usage: %s <command> [<flags>] [file1 dir1 ... fileOrDirN]\n\n", filepath.Base(os.Args[0]))
 		fmt.Fprintf(os.Stderr, "\nCommands:\n")
 		fmt.Fprintf(os.Stderr, "\n  convert\n    \tConvert archive or document\n\n")
-		order := []string{"width", "height", "fit", "dpi", "format", "archive", "zip-level", "quality", "effort", "lossless", "combine", "outfile", "filter", "no-cover", "no-rgb",
+		order := []string{"width", "height", "fit", "no-upscale", "dpi", "format", "archive", "zip-level", "quality", "effort", "lossless", "combine", "outfile", "filter", "no-cover", "no-rgb",
 			"no-nonimage", "no-convert", "grayscale", "rotate", "brightness", "contrast", "suffix", "outdir", "size", "recursive", "quiet"}
 		for _, name := range order {
 			f := convert.Lookup(name)
@@ -264,14 +267,14 @@ func parseFlags() (cbconvert.Options, []string) {
 			fmt.Fprintf(os.Stderr, "%v (default %q)\n", f.Usage, f.DefValue)
 		}
 		fmt.Fprintf(os.Stderr, "\n  cover\n    \tExtract cover\n\n")
-		order = []string{"width", "height", "fit", "dpi", "format", "quality", "effort", "lossless", "filter", "outdir", "size", "recursive", "quiet"}
+		order = []string{"width", "height", "fit", "no-upscale", "dpi", "format", "quality", "effort", "lossless", "filter", "outdir", "size", "recursive", "quiet"}
 		for _, name := range order {
 			f := cover.Lookup(name)
 			fmt.Fprintf(os.Stderr, "    --%s\n    \t", f.Name)
 			fmt.Fprintf(os.Stderr, "%v (default %q)\n", f.Usage, f.DefValue)
 		}
 		fmt.Fprintf(os.Stderr, "\n  thumbnail\n    \tExtract cover thumbnail (freedesktop spec.)\n\n")
-		order = []string{"width", "height", "fit", "dpi", "filter", "outdir", "outfile", "size", "recursive", "quiet"}
+		order = []string{"width", "height", "fit", "no-upscale", "dpi", "filter", "outdir", "outfile", "size", "recursive", "quiet"}
 		for _, name := range order {
 			f := thumbnail.Lookup(name)
 			fmt.Fprintf(os.Stderr, "    --%s\n    \t", f.Name)