imageopt

package

v1.1.9 Latest Latest Go to latest Published: Oct 29, 2026 License: GPL-3.0 Imports: 9 Imported by: 0

Details

Valid go.mod file
Redistributable license
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Stable version
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Repository

github.com/mhdna/kashi

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Documentation ¶

Overview ¶

Package imageopt turns arbitrary uploaded photos into small, good-looking WebP files. It is shared by the upload handlers (api) and the one-off backfill command (cmd/optimize_images) so both produce identical output.

Index ¶

Constants
func Decode(data []byte, maxDim int) (img image.Image, resized bool, err error)
func EncodeWebP(img image.Image, quality int) ([]byte, error)
type Result
- func Optimize(original []byte, declaredContentType, declaredExt string) Result

Constants ¶

View Source

const (
	// MaxDim caps the long edge. 1920px keeps small print on a receipt
	// legible while shrinking a 12MP phone photo to a fraction of its size.
	MaxDim = 1920
	// Quality is libwebp's lossy 0-100 scale; ~75 is the "good, not
	// pristine" knee -- visually close to the source at roughly a quarter of
	// the JPEG bytes.
	Quality = 75

	ContentType = "image/webp"
	Ext         = ".webp"
)

Variables ¶

This section is empty.

Functions ¶

func Decode ¶

func Decode(data []byte, maxDim int) (img image.Image, resized bool, err error)

Decode returns the decoded, orientation-corrected image, downscaled if its long edge exceeds maxDim; resized reports whether that downscale happened.

func EncodeWebP ¶

func EncodeWebP(img image.Image, quality int) ([]byte, error)

EncodeWebP encodes img as lossy WebP, holding one of the bounded encode slots for the duration.

Types ¶

type Result ¶

type Result struct {
	Data        []byte
	ContentType string
	Ext         string
	// Optimized is false when the original bytes were kept unchanged.
	Optimized bool
}

Result is what a caller persists: the bytes to write and the metadata that must describe *those* bytes (not the original upload).

func Optimize ¶

func Optimize(original []byte, declaredContentType, declaredExt string) Result

Optimize decodes the photo (honouring EXIF orientation, which a re-encode would otherwise drop and leave phone photos sideways), downsizes it to MaxDim, and re-encodes it as lossy WebP.

It never makes an image worse: if the result isn't smaller than the original, or the format can't be decoded here (e.g. HEIC), the original bytes come back unchanged under their declared type.

Source Files ¶

View all Source files

imageopt.go

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