pngmeta

package main

import (
	"fmt"
	"github.com/mandykoh/prism/meta"
	"github.com/mandykoh/prism/meta/pngmeta"
	"image"
	"image/png"
	"os"
)

func printMetadata(md *meta.Data, img image.Image) {
	fmt.Printf("Format: %s\n", md.Format)
	fmt.Printf("BitsPerComponent: %d\n", md.BitsPerComponent)
	fmt.Printf("PixelHeight: %d\n", md.PixelHeight)
	fmt.Printf("PixelWidth: %d\n", md.PixelWidth)

	fmt.Printf("Actual image height: %d\n", img.Bounds().Dy())
	fmt.Printf("Actual image width: %d\n", img.Bounds().Dx())
}

func main() {
	inFile, err := os.Open("../../test-images/pizza-rgb8-srgb.png")
	if err != nil {
		panic(err)
	}
	defer inFile.Close()

	md, imgStream, err := pngmeta.Load(inFile)
	if err != nil {
		panic(err)
	}

	img, err := png.Decode(imgStream)
	if err != nil {
		panic(err)
	}

	printMetadata(md, img)

}

Output:

Format: PNG
BitsPerComponent: 8
PixelHeight: 1200
PixelWidth: 1200
Actual image height: 1200
Actual image width: 1200

package main

import (
	"fmt"
	"github.com/mandykoh/prism/meta"
	"github.com/mandykoh/prism/meta/pngmeta"
	"image/png"
	"os"
)

func printICCProfile(md *meta.Data) {
	profile, err := md.ICCProfile()
	if err != nil {
		panic(err)
	}

	fmt.Printf("ProfileSize: %d\n", profile.Header.ProfileSize)
	fmt.Printf("PreferredCMM: %v\n", profile.Header.PreferredCMM)
	fmt.Printf("ProfileVersion: %s\n", profile.Header.Version)
	fmt.Printf("DeviceClass: %s\n", profile.Header.DeviceClass)
	fmt.Printf("DataColorSpace: %s\n", profile.Header.DataColorSpace)
	fmt.Printf("PCS: %s\n", profile.Header.ProfileConnectionSpace)
	fmt.Printf("CreatedAt: %v\n", profile.Header.CreatedAt)
	fmt.Printf("PrimaryPlatform: %v\n", profile.Header.PrimaryPlatform)
	fmt.Printf("Embedded: %v\n", profile.Header.Embedded)
	fmt.Printf("DependsOnEmbeddedData: %v\n", profile.Header.DependsOnEmbeddedData)
	fmt.Printf("DeviceManufacturer: %s\n", profile.Header.DeviceManufacturer)
	fmt.Printf("DeviceModel: %s\n", profile.Header.DeviceModel)
	fmt.Printf("DeviceAttributes: %064b\n", profile.Header.DeviceAttributes)
	fmt.Printf("RenderingIntent: %v\n", profile.Header.RenderingIntent)
	fmt.Printf("PCSIlluminant: %v\n", profile.Header.PCSIlluminant)
	fmt.Printf("ProfileCreator: %v\n", profile.Header.ProfileCreator)
	fmt.Printf("ProfileID: %0x\n", profile.Header.ProfileID)

	if desc, err := profile.Description(); err != nil {
		panic(err)
	} else {
		fmt.Printf("Description: %s\n", desc)
	}
}

func main() {
	inFile, err := os.Open("../../test-images/pizza-rgb8-srgb.png")
	if err != nil {
		panic(err)
	}
	defer inFile.Close()

	md, imgStream, err := pngmeta.Load(inFile)
	if err != nil {
		panic(err)
	}

	_, err = png.Decode(imgStream)
	if err != nil {
		panic(err)
	}

	printICCProfile(md)

}

Output:

ProfileSize: 596
PreferredCMM: 'lcms'
ProfileVersion: 4.3.0
DeviceClass: Display
DataColorSpace: RGB
PCS: XYZ
CreatedAt: 2020-08-12 21:45:21 +0000 UTC
PrimaryPlatform: Apple Computer, Inc.
Embedded: false
DependsOnEmbeddedData: false
DeviceManufacturer: '    '
DeviceModel: '    '
DeviceAttributes: 0000000000000000000000000000000000000000000000000000000000000000
RenderingIntent: Perceptual
PCSIlluminant: [63190 65536 54061]
ProfileCreator: 'lcms'
ProfileID: 00000000000000000000000000000000
Description: sRGB IEC61966-2.1