package imaging_test

import (
    "image"
    "image/color"
    "log"

    "github.com/disintegration/imaging"
)

func Example() {
    // Open a test image.
    src, err := imaging.Open("testdata/flowers.png")
    if err != nil {
        log.Fatalf("failed to open image: %v", err)
    }

    // Crop the original image to 300x300px size using the center anchor.
    src = imaging.CropAnchor(src, 300, 300, imaging.Center)

    // Resize the cropped image to width = 200px preserving the aspect ratio.
    src = imaging.Resize(src, 200, 0, imaging.Lanczos)

    // Create a blurred version of the image.
    img1 := imaging.Blur(src, 5)

    // Create a grayscale version of the image with higher contrast and sharpness.
    img2 := imaging.Grayscale(src)
    img2 = imaging.AdjustContrast(img2, 20)
    img2 = imaging.Sharpen(img2, 2)

    // Create an inverted version of the image.
    img3 := imaging.Invert(src)

    // Create an embossed version of the image using a convolution filter.
    img4 := imaging.Convolve3x3(
        src,
        [9]float64{
            -1, -1, 0,
            -1, 1, 1,
            0, 1, 1,
        },
        nil,
    )

    // Create a new image and paste the four produced images into it.
    dst := imaging.New(400, 400, color.NRGBA{0, 0, 0, 0})
    dst = imaging.Paste(dst, img1, image.Pt(0, 0))
    dst = imaging.Paste(dst, img2, image.Pt(0, 200))
    dst = imaging.Paste(dst, img3, image.Pt(200, 0))
    dst = imaging.Paste(dst, img4, image.Pt(200, 200))

    // Save the resulting image as JPEG.
    err = imaging.Save(dst, "testdata/out_example.jpg")
    if err != nil {
        log.Fatalf("failed to save image: %v", err)
    }
}