images/manipulation.go
package images
import (
"bytes"
"fmt"
"image"
"image/color"
"image/draw"
"image/png"
"math"
"os"
"github.com/nfnt/resize"
"github.com/oliamb/cutter"
"go.uber.org/zap"
xdraw "golang.org/x/image/draw"
"github.com/ethereum/go-ethereum/log"
)
type Circle struct {
X, Y, R int
}
func (c *Circle) ColorModel() color.Model {
return color.AlphaModel
}
func (c *Circle) Bounds() image.Rectangle {
return image.Rect(c.X-c.R, c.Y-c.R, c.X+c.R, c.Y+c.R)
}
func (c *Circle) At(x, y int) color.Color {
xx, yy, rr := float64(x-c.X)+0.5, float64(y-c.Y)+0.5, float64(c.R)
if xx*xx+yy*yy < rr*rr {
return color.Alpha{255}
}
return color.Alpha{0}
}
func Resize(size ResizeDimension, img image.Image) image.Image {
var width, height uint
switch {
case img.Bounds().Max.X == img.Bounds().Max.Y:
width, height = uint(size), uint(size)
case img.Bounds().Max.X > img.Bounds().Max.Y:
width, height = 0, uint(size)
default:
width, height = uint(size), 0
}
log.Info("resizing", "size", size, "width", width, "height", height)
return resize.Resize(width, height, img, resize.Bilinear)
}
func ResizeTo(percent int, img image.Image) image.Image {
width := uint(img.Bounds().Max.X * percent / 100)
height := uint(img.Bounds().Max.Y * percent / 100)
return resize.Resize(width, height, img, resize.Bilinear)
}
func ShrinkOnly(size ResizeDimension, img image.Image) image.Image {
finalSize := int(math.Min(float64(size), math.Min(float64(img.Bounds().Dx()), float64(img.Bounds().Dy()))))
return Resize(ResizeDimension(finalSize), img)
}
func Crop(img image.Image, rect image.Rectangle) (image.Image, error) {
if img.Bounds().Max.X < rect.Max.X || img.Bounds().Max.Y < rect.Max.Y {
return nil, fmt.Errorf(
"crop dimensions out of bounds of image, image width '%dpx' & height '%dpx'; crop bottom right coordinate at X '%dpx' Y '%dpx'",
img.Bounds().Max.X, img.Bounds().Max.Y,
rect.Max.X, rect.Max.Y,
)
}
return cutter.Crop(img, cutter.Config{
Width: rect.Dx(),
Height: rect.Dy(),
Anchor: rect.Min,
})
}
// CropCenter takes an image, usually downloaded from a URL
// If the image is square, the full image is returned
// If the image is rectangular, the largest central square is returned
// calculations at _docs/image-center-crop-calculations.png
func CropCenter(img image.Image) (image.Image, error) {
var cropRect image.Rectangle
maxBounds := img.Bounds().Max
if maxBounds.X == maxBounds.Y {
return img, nil
}
if maxBounds.X > maxBounds.Y {
// the final output should be YxY
cropRect = image.Rectangle{
Min: image.Point{X: maxBounds.X/2 - maxBounds.Y/2, Y: 0},
Max: image.Point{X: maxBounds.X/2 + maxBounds.Y/2, Y: maxBounds.Y},
}
} else {
// the final output should be XxX
cropRect = image.Rectangle{
Min: image.Point{X: 0, Y: maxBounds.Y/2 - maxBounds.X/2},
Max: image.Point{X: maxBounds.X, Y: maxBounds.Y/2 + maxBounds.X/2},
}
}
return Crop(img, cropRect)
}
func ImageToBytes(imagePath string) ([]byte, error) {
// Open the image file
file, err := os.Open(imagePath)
if err != nil {
return nil, err
}
defer file.Close()
// Decode the image
img, _, err := image.Decode(file)
if err != nil {
return nil, err
}
// Create a new buffer to hold the image data
var imgBuffer bytes.Buffer
// Encode the image to the desired format and save it in the buffer
err = png.Encode(&imgBuffer, img)
if err != nil {
return nil, err
}
// Return the image data as a byte slice
return imgBuffer.Bytes(), nil
}
func ImageToBytesAndImage(imagePath string) ([]byte, image.Image, error) {
// Open the image file
file, err := os.Open(imagePath)
if err != nil {
return nil, nil, err
}
defer file.Close()
// Decode the image
img, _, err := image.Decode(file)
if err != nil {
return nil, nil, err
}
// Create a new buffer to hold the image data
var imgBuffer bytes.Buffer
// Encode the image to the desired format and save it in the buffer
err = png.Encode(&imgBuffer, img)
if err != nil {
return nil, nil, err
}
// Return the image data as a byte slice
return imgBuffer.Bytes(), img, nil
}
func AddPadding(img image.Image, padding int) *image.RGBA {
bounds := img.Bounds()
newBounds := image.Rect(bounds.Min.X-padding, bounds.Min.Y-padding, bounds.Max.X+padding, bounds.Max.Y+padding)
paddedImg := image.NewRGBA(newBounds)
draw.Draw(paddedImg, newBounds, &image.Uniform{C: color.White}, image.ZP, draw.Src)
return paddedImg
}
func EncodePNG(img *image.RGBA) ([]byte, error) {
resultImg := &bytes.Buffer{}
err := png.Encode(resultImg, img)
if err != nil {
return nil, err
}
return resultImg.Bytes(), nil
}
func CreateCircleWithPadding(img image.Image, padding int) *image.RGBA {
bounds := img.Bounds()
width := bounds.Dx()
// only relying on width as a metric here because we know that we
// store profile images in a perfect circle
radius := width / 2
paddedWidth := width + 2*padding
paddedRadius := paddedWidth / 2
// Create a new circular image with padding
newBounds := image.Rect(0, 0, paddedWidth, paddedWidth)
circle := image.NewRGBA(newBounds)
// Create a larger circular mask for the padding
paddingMask := &Circle{
X: paddedRadius,
Y: paddedRadius,
R: paddedRadius,
}
// Draw the white color onto the circle with padding mask
draw.DrawMask(circle, circle.Bounds(), image.NewUniform(color.White), image.ZP, paddingMask, image.ZP, draw.Src)
// Create a new circle mask with the original size
circleMask := &Circle{
X: radius,
Y: radius,
R: radius,
}
// Draw the original image onto the white circular image at the center (with padding offset)
draw.DrawMask(circle, bounds.Add(image.Pt(padding, padding)), img, image.ZP, circleMask, image.ZP, draw.Over)
return circle
}
func RoundCrop(inputImage []byte) ([]byte, error) {
img, _, err := image.Decode(bytes.NewReader(inputImage))
if err != nil {
return nil, err
}
result := CreateCircleWithPadding(img, 0)
var outputImage bytes.Buffer
err = png.Encode(&outputImage, result)
if err != nil {
return nil, err
}
return outputImage.Bytes(), nil
}
func PlaceCircleInCenter(paddedImg, circle *image.RGBA) *image.RGBA {
bounds := circle.Bounds()
centerX := (paddedImg.Bounds().Min.X + paddedImg.Bounds().Max.X) / 2
centerY := (paddedImg.Bounds().Min.Y + paddedImg.Bounds().Max.Y) / 2
draw.Draw(paddedImg, bounds.Add(image.Pt(centerX-bounds.Dx()/2, centerY-bounds.Dy()/2)), circle, image.ZP, draw.Over)
return paddedImg
}
func ResizeImage(imgBytes []byte, width, height int) ([]byte, error) {
// Decode image bytes
img, _, err := image.Decode(bytes.NewReader(imgBytes))
if err != nil {
return nil, err
}
// Create a new image with the desired dimensions
newImg := image.NewNRGBA(image.Rect(0, 0, width, height))
xdraw.BiLinear.Scale(newImg, newImg.Bounds(), img, img.Bounds(), draw.Over, nil)
// Encode the new image to bytes
var newImgBytes bytes.Buffer
if err = png.Encode(&newImgBytes, newImg); err != nil {
return nil, err
}
return newImgBytes.Bytes(), nil
}
func SuperimposeLogoOnQRImage(imageBytes []byte, qrFilepath []byte) []byte {
// Read the two images from bytes
img1, _, err := image.Decode(bytes.NewReader(imageBytes))
if err != nil {
log.Error("error decoding logo Image", zap.Error(err))
return nil
}
img2, _, err := image.Decode(bytes.NewReader(qrFilepath))
if err != nil {
log.Error("error decoding QR Image", zap.Error(err))
return nil
}
// Create a new image with the dimensions of the first image
result := image.NewRGBA(img1.Bounds())
// Draw the first image on the new image
draw.Draw(result, img1.Bounds(), img1, image.ZP, draw.Src)
// Get the dimensions of the second image
img2Bounds := img2.Bounds()
// Calculate the x and y coordinates to center the second image
x := (img1.Bounds().Dx() - img2Bounds.Dx()) / 2
y := (img1.Bounds().Dy() - img2Bounds.Dy()) / 2
// Draw the second image on top of the first image at the calculated coordinates
draw.Draw(result, img2Bounds.Add(image.Pt(x, y)), img2, image.ZP, draw.Over)
// Encode the final image to a desired format
var b bytes.Buffer
err = png.Encode(&b, result)
if err != nil {
log.Error("error encoding final result Image to Buffer", zap.Error(err))
return nil
}
return b.Bytes()
}