Documentation
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Index ¶
- func CropImage(img image.Image, crop image.Rectangle) image.Image
- func Open(fileName string) (image.Image, error)
- func OpenOpts(fileName string, autoOrientation bool, srcBytes bool) (image.Image, []byte, error)
- func RotateAndCropFile(source string, dest string, opts Options) error
- func RotateImage(img image.Image, angle int) image.Image
- func Save(image image.Image, fileName string) error
- func SaveOpts(image image.Image, fileName string, quality int, srcExif []byte) error
- func TransformFile(source string, destinations map[string]Options) error
- type CropAnchor
- type Options
- type ResampleStrategy
- type TransformType
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func OpenOpts ¶ added in v0.0.11
OpenOpts opens an Image for editing. Possibly returning the src file as a byte slice
func RotateAndCropFile ¶ added in v0.0.11
RotateAndCropFile rotates and crops an image file and saves the result
func RotateImage ¶ added in v0.0.11
RotateImage rotates an image. Negative angle indicates a counter clockwise rotation
func SaveOpts ¶ added in v0.0.11
SaveOpts saves an image. If srcExif is != nil it will try to extract and exif information from that and append it to the new file
func TransformFile ¶
TransformFile creates versions of source based on destinations. Supported formats are "gif", "tif", "bmp", "jpg", and "png". Quality and CopyExif are only supported for jpg images. Transform file uses the file extension to determine input and output format
Example ¶
sourceImg := "../assets/leica.jpg"
homeDir, _ := os.UserHomeDir()
sourceDir := path.Join(homeDir, "transform")
_ = os.Mkdir(sourceDir, 0755)
//for all but the thumb we are copying the original meta information
thumb := NewOptions(ResizeAndCrop, 400, 400, false)
landscape := NewOptions(ResizeAndCrop, 1200, 628, true)
square := NewOptions(ResizeAndCrop, 1200, 1200, true)
portrait := NewOptions(ResizeAndCrop, 1080, 1350, true)
resize := NewOptions(Resize, 1200, 0, true)
destImgs := map[string]Options{
path.Join(sourceDir, "thumb.jpg"): thumb,
path.Join(sourceDir, "landscape.jpg"): landscape,
path.Join(sourceDir, "square.jpg"): square,
path.Join(sourceDir, "portrait.jpg"): portrait,
path.Join(sourceDir, "resize.jpg"): resize,
}
_ = TransformFile(sourceImg, destImgs)
fmt.Println("Transformed leica.jpg")
Output: Transformed leica.jpg
Types ¶
type CropAnchor ¶
type CropAnchor int
CropAnchor specifies where the anchor point should be when cropping an image
const ( Center CropAnchor = iota TopLeft Top TopRight Left Right BottomLeft Bottom BottomRight )
Various Anchors for your crop
type Options ¶
type Options struct {
Width int
Height int
Quality int
Anchor CropAnchor
Transform TransformType
Strategy ResampleStrategy
X int
Y int
Angle int
CopyExif bool
}
Options holds all options for a given image transformation job
func NewOptions ¶
func NewOptions(transform TransformType, width, height int, copyExif bool) Options
NewOptions creates Options that default to crop center strategy, image quality 90% and Resize strategy lanczos
type ResampleStrategy ¶
type ResampleStrategy int
ResampleStrategy specifies what method to use when resampling an image
const ( //Lanczos sampling. Default Lanczos ResampleStrategy = iota //NearestNeighbor sampling NearestNeighbor //Box sampling Box //Linear sampling Linear //Hermite sampling Hermite //MitchellNetravali sampling MitchellNetravali //CatmullRom sampling CatmullRom //BSpline sampling BSpline //Gaussian sampling Gaussian //Bartlett sampling Bartlett //Hann sampling Hann //Hamming sampling Hamming //Blackman sampling Blackman //Welch sampling Welch //Cosine sampling Cosine )
type TransformType ¶
type TransformType int
TransformType specifies how to transform an image, crop, resize, etc...
const ( //ResizeAndCrop scales the image to given dimension. To keep aspect ratio the image is cropped ResizeAndCrop TransformType = iota //Crop cuts a specified region of the image Crop //Resize scale the image to the specified dimensions. To keep aspect ratio set either width or height to 0 Resize //ResizeAndFit scale the image to fit the maximum specified dimensions. ResizeAndFit )
Source Files