Documentation
¶
Overview ¶
Package webp implements an WEBP image decoder based on libwebp compiled to WASM.
Index ¶
- Constants
- Variables
- func Decode(r io.Reader, opts ...Options) (image.Image, error)
- func DecodeConfig(r io.Reader) (image.Config, error)
- func Dynamic() error
- func Encode(w io.Writer, m image.Image, o ...Options) error
- func EncodeAll(w io.Writer, anim *WEBP, o ...Options) error
- type Exif
- type Options
- type WEBP
Constants ¶
View Source
const DefaultMethod = 4
DefaultMethod is the default method encoding parameter.
View Source
const DefaultQuality = 75
DefaultQuality is the default quality encoding parameter.
Variables ¶
View Source
var ( ErrMemRead = errors.New("webp: mem read failed") ErrMemWrite = errors.New("webp: mem write failed") ErrDecode = errors.New("webp: decode failed") ErrEncode = errors.New("webp: encode failed") )
Errors .
View Source
var ErrNoExif = errors.New("webp: no exif data")
ErrNoExif is returned by DecodeExif when the WEBP has no EXIF chunk.
Functions ¶
func Decode ¶
Decode reads a WEBP image from r; pass Options{AutoRotate: true} to apply the EXIF orientation.
func DecodeConfig ¶
DecodeConfig returns the color model and dimensions of a WEBP image without decoding the entire image.
func Dynamic ¶ added in v0.2.2
func Dynamic() error
Dynamic returns error (if there was any) during opening dynamic/shared library.
Types ¶
type Exif ¶ added in v0.6.2
type Exif struct {
// Basic image info
Orientation int // EXIF orientation (1-8). 1 = normal, values 2-8 indicate rotation/flip.
Width int // Image width in pixels.
Height int // Image height in pixels.
// Camera info
Make string // Camera manufacturer (e.g., "Canon").
Model string // Camera model (e.g., "Canon EOS 5D Mark III").
Software string // Software used to process/create the image.
// Date/Time (format: "YYYY:MM:DD HH:MM:SS")
DateTime string // File modification date/time.
DateTimeOriginal string // Original capture date/time (when photo was taken).
// Exposure settings
ExposureTime float64 // Shutter speed in seconds (e.g., 0.004 = 1/250s).
FNumber float64 // Aperture f-number (e.g., 5.6 = f/5.6).
ISOSpeed int // ISO speed rating (e.g., 800).
FocalLength float64 // Lens focal length in millimeters.
Flash int // Flash mode/status (0 = no flash, non-zero = flash fired).
// GPS location
GPSLatitude float64 // Latitude in decimal degrees (positive = North, negative = South).
GPSLongitude float64 // Longitude in decimal degrees (positive = East, negative = West).
GPSAltitude float64 // Altitude in meters above sea level.
// Copyright/Author
Copyright string // Copyright notice.
Artist string // Creator/photographer name.
}
Exif holds the EXIF metadata decoded from a WEBP image.
type Options ¶ added in v0.2.4
type Options struct {
// Quality in the range [0,100]. Default is 75.
Quality int
// Lossless enables lossless compression. Lossless ignores quality.
Lossless bool
// Method is quality/speed trade-off (0=fast, 6=slower-better). Default is 4.
Method int
// Exact preserve the exact RGB values in transparent area.
Exact bool
// AutoRotate applies the EXIF orientation to the decoded image (Decode/DecodeAll only).
AutoRotate bool
}
Options are the encoding parameters, plus AutoRotate which applies to Decode.
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