Documentation
¶
Overview ¶
Package autometa provides support for embedded metadata and automatic detection of image formats.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Load ¶
Load loads the metadata for an image stream, which may be one of the supported image formats.
Only as much of the stream is consumed as necessary to extract the metadata; the returned stream contains a buffered copy of the consumed data such that reading from it will produce the same results as fully reading the input stream. This provides a convenient way to load the full image after loading the metadata.
An error is returned if basic metadata could not be extracted. The returned stream still provides the full image data.
Example (BasicJPEGMetadata) ¶
package main
import (
"fmt"
"image"
"image/jpeg"
"os"
"github.com/mandykoh/prism/meta"
"github.com/mandykoh/prism/meta/autometa"
)
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.jpg")
if err != nil {
panic(err)
}
defer inFile.Close()
md, imgStream, err := autometa.Load(inFile)
if err != nil {
panic(err)
}
img, err := jpeg.Decode(imgStream)
if err != nil {
panic(err)
}
printMetadata(md, img)
}
Output: Format: JPEG BitsPerComponent: 8 PixelHeight: 1200 PixelWidth: 1200 Actual image height: 1200 Actual image width: 1200
Example (BasicPNGMetadata) ¶
package main
import (
"fmt"
"image"
"image/png"
"os"
"github.com/mandykoh/prism/meta"
"github.com/mandykoh/prism/meta/autometa"
)
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 := autometa.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
Example (BasicWebPMetadata) ¶
package main
import (
"fmt"
"image"
"os"
"github.com/mandykoh/prism/meta"
"github.com/mandykoh/prism/meta/autometa"
"golang.org/x/image/webp"
)
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-displayp3-vp8x.webp")
if err != nil {
panic(err)
}
defer inFile.Close()
md, imgStream, err := autometa.Load(inFile)
if err != nil {
panic(err)
}
img, err := webp.Decode(imgStream)
if err != nil {
panic(err)
}
printMetadata(md, img)
}
Output: Format: WebP BitsPerComponent: 8 PixelHeight: 1200 PixelWidth: 1200 Actual image height: 1200 Actual image width: 1200
Types ¶
This section is empty.
Source Files
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