Example of using bep/imagemeta (https://github.com/bep/imagemeta)

exif.go

package main

import (
	"fmt"
	"maps"
	"os"
	"regexp"
	"slices"
	"strings"
	"time"

	"github.com/bep/imagemeta"
)

// ExifInfo holds the decoded Exif data for an Image. The main fields
// are picked out by name, with other residual fields that match the
// package (private) filtering regex held in Tags.
type ExifInfo struct {
	// GPS latitude in degrees.
	Lat float64

	// GPS longitude in degrees.
	Long float64

	// Image creation date/time.
	Date time.Time

	// Aperture
	Aperture float64

	// F Number
	FNumber float64

	// LensModel
	LensModel string

	// Original Image Width
	Width uint32

	// Original Image Height
	Height uint32

	// Original orientation
	Orientation uint16

	// Shutterspeed
	ShutterSpeed float64

	// A collection of tags for this Image matching the
	// interestingTagsRegexp, GPS and Time matches.
	Tags imagemeta.Tags
}

// Map returns a map[string]any of fields of ExifInfo.
func (e *ExifInfo) Map() map[string]any {
	m := map[string]any{}
	m["Lat"] = e.Lat
	m["Long"] = e.Long
	m["Date"] = e.Date
	m["Aperture"] = e.Aperture
	m["FNumber"] = e.FNumber
	m["LensModel"] = e.LensModel
	m["Width"] = e.Width
	m["Height"] = e.Height
	m["Orientation"] = e.Orientation
	m["ShutterSpeed"] = e.ShutterSpeed
	return m
}

// Keys returns the sorted keys of ExifInfo.
func (e *ExifInfo) Keys() []string {
	return slices.Sorted(maps.Keys(e.Map()))
}

func main() {

	// see hugo:resources/images/exif/exif.go

	interestingTagsRegexp := regexp.MustCompile(
		`Aperture|ShutterSpeed|Lens|FNumber|Height|Width|Orientation`,
	)

	img, err := os.Open("IMG_4708.JPG")
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	shouldInclude := func(ti imagemeta.TagInfo) bool {
		if ti.Source == imagemeta.EXIF {
			if strings.Contains(ti.Tag, "Time") {
				return true
			}
			// GPS tags are needed for lat/long.
			if strings.HasPrefix(ti.Tag, "GPS") {
				return true
			}
			// Drop thumbnail tags.
			if !strings.HasPrefix(ti.Namespace, "IFD0") {
				return false
			}
		}
		if interestingTagsRegexp.MatchString(ti.Tag) {
			return true
		}
		return false // all other tags will be exlcuded
	}

	var ei ExifInfo
	handleTag := func(ti imagemeta.TagInfo) error {
		ei.Tags.Add(ti)
		return nil
	}

	err = imagemeta.Decode(
		imagemeta.Options{
			R:               img,
			ImageFormat:     imagemeta.JPEG,
			ShouldHandleTag: shouldInclude,
			HandleTag:       handleTag,
			Sources:         imagemeta.EXIF,
		},
	)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	ei.Date, _ = ei.Tags.GetDateTime()
	ei.Lat, ei.Long, _ = ei.Tags.GetLatLong()

	if tag, ok := ei.Tags.EXIF()["ApertureValue"]; ok {
		ei.Aperture = tag.Value.(float64)
	}
	if tag, ok := ei.Tags.EXIF()["LensModel"]; ok {
		ei.LensModel = tag.Value.(string)
	}
	if tag, ok := ei.Tags.EXIF()["ExifImageWidth"]; ok {
		ei.Width = tag.Value.(uint32)
	}
	if tag, ok := ei.Tags.EXIF()["ExifImageHeight"]; ok {
		ei.Height = tag.Value.(uint32)
	}
	if tag, ok := ei.Tags.EXIF()["Orientation"]; ok {
		ei.Orientation = tag.Value.(uint16)
	}
	if tag, ok := ei.Tags.EXIF()["FNumber"]; ok {
		if n, ok := tag.Value.(imagemeta.Rat[uint32]); ok {
			ei.FNumber = n.Float64()
		}
	}
	if tag, ok := ei.Tags.EXIF()["ShutterSpeedValue"]; ok {
		ei.ShutterSpeed = tag.Value.(float64)
	}

	for _, k := range ei.Keys() {
		fmt.Printf("%12s : %v\n", k, ei.asMap()[k])
	}
	
	// ei.Tags = imagemeta.Tags{} // Remove all tags for printing

	fmt.Printf("%#v\n", ei)
}