add resolution maximums

README.md

@@ -1,7 +1,11 @@
 # imageoptimizer
 
 imageoptimizer is a tool for bulk compression og JPG images. It will re-compress original images and replace them if the savings is
-more than the requested percentage difference and optionally if the original file is bigger than a cefrtain size. By default it operates in a "dry run" mode where images are not replaced but individual and total savings are reported at the end, unless you supply the '-replace' flag.
+more than the requested percentage difference and optionally if the original file is bigger than a cefrtain size. You can also
+set a maximum resolution for images and they will be rescaled if they exceed it, however they are only replaced if they meet the size
+difference requirement set.
+
+By default it operates in a "dry run" mode where images are not replaced but individual and total savings are reported at the end, unless you supply the '-replace' flag.
 
 # why?
 

go.mod

@@ -1,3 +1,5 @@
 module git.teamworkapps.com/shortcut/imageoptimizer
 
 go 1.17
+
+require github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 // indirect

go.sum

@@ -0,0 +1,2 @@
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6Oo2LfFZAehjjQMERAvZLEDnQ=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=

main.go

@@ -8,6 +8,8 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"github.com/nfnt/resize"
 )
 
 type config struct {
@@ -18,6 +20,8 @@ type config struct {
 	StartingPath  string
 	Quiet bool
 		AtLeast	uint
+		MaxWidth uint
+		MaxHeight uint
 
 }
 
@@ -36,6 +40,8 @@ func main() {
 	flag.UintVar(&c.Quality, "quality", 85, "JPG compression quality level.")
 	flag.BoolVar(&c.Quiet, "quiet", false, "Less output - don't print per-file detail")
 	flag.UintVar(&c.AtLeast, "atleast", 0, "Ignore images that aren't at least this many kilobytes")
+	flag.UintVar(&c.MaxWidth, "maxwidth", 0, "Maximum width, scale images bigger to fit within this width. 0 ignores. Won't replace unless it meets the diff threashold.")
+	flag.UintVar(&c.MaxHeight, "maxheight", 0, "Maximum height, scale images bigger to fit within this height. 0 ignores. Won't replace until it meets the diff threashold.")
 	flag.StringVar(&c.StartingPath, "startingpath", ".", "Start from this path instead of current working dir")
 	flag.BoolVar(&c.Replace, "replace", false, "Replace with compressed versions if criteria are met. Otheriwse, just test and report, don't replace any images. (default false)")
 	flag.Parse()
@@ -123,6 +129,12 @@ func doSingleImage(f string, c config, s stats) stats {
 		return s
 	}
 	in.Close()
+	// Check bounds and resize if necessary
+	ores:=orig.Bounds()
+	if (c.MaxWidth !=0 && ores.Dx() > int(c.MaxWidth) ) || (c.MaxHeight!=0 && ores.Dy()>int(c.MaxHeight)) {
+		orig=resize.Thumbnail(c.MaxWidth, c.MaxHeight, orig, resize.Lanczos3)
+		fmt.Printf("Resized from %dx%d - ", ores.Dx(), ores.Dy())
+	}
 	out, err := os.OpenFile("imageoptimizer.tmp", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, st.Mode())
 	if err != nil {
 		fmt.Printf("Couldn't open out temprary file: %s\n", err.Error())