Image Class - Soli MVC Documentation

Supported Formats

JPEG PNG GIF WebP BMP TIFF ICO

All methods return a new Image instance, enabling fluent chaining.

Loading Images

Image.new(path)

Loads an image from a file path. The format is detected automatically.

Parameters

path : String - Path to the image file

Returns

Image instance

let img = Image.new("photo.jpg")
println(img.width)   # 1920
println(img.height)  # 1080

Image.from_buffer(base64_string)

Loads an image from a base64-encoded string. Useful for processing images from HTTP requests, S3, or databases.

Parameters

base64_string : String - Base64-encoded image data

Returns

Image instance

let img = Image.from_buffer(base64_data)
println(img.width)

Properties

img.width / img.height

Returns the image dimensions in pixels.

Returns

Int

let img = Image.new("photo.jpg")
println("Size: " + str(img.width) + "x" + str(img.height))

Resizing

img.resize(width, height)

Resizes the image to the specified dimensions using high-quality Lanczos3 filtering.

Parameters

width : Int - Target width in pixels

height : Int - Target height in pixels

Returns

New Image instance

let resized = Image.new("photo.jpg").resize(800, 600)
resized.to_file("photo_resized.jpg")

img.thumbnail(max_size)

Creates a thumbnail that fits within a square of the given size, preserving the original aspect ratio.

Parameters

max_size : Int - Maximum width or height in pixels

Returns

New Image instance

let thumb = Image.new("photo.jpg").thumbnail(200)
thumb.to_file("thumb.jpg")

img.crop(x, y, width, height)

Crops a rectangular region from the image. Coordinates must be non-negative.

Parameters

x : Int - Left offset (>= 0)

y : Int - Top offset (>= 0)

width : Int - Crop width

height : Int - Crop height

Returns

New Image instance

let cropped = Image.new("photo.jpg").crop(100, 50, 400, 300)
cropped.to_file("cropped.jpg")

Transforms

img.grayscale()

Convert to grayscale.

img.invert()

Invert all colors.

img.flip_horizontal()

Flip horizontally (mirror).

img.flip_vertical()

Flip vertically.

img.rotate90()

Rotate 90° clockwise.

img.rotate180()

Rotate 180°.

img.rotate270()

Rotate 270° clockwise (90° counter-clockwise).

All transform methods return a new Image and can be chained:

let img = Image.new("photo.jpg")
    .grayscale()
    .flip_horizontal()
    .rotate90()
img.to_file("transformed.jpg")

Adjustments

img.blur(sigma)

Applies a Gaussian blur. Higher sigma = more blur.

Parameters

sigma : Float or Int - Blur intensity

let blurred = Image.new("photo.jpg").blur(3.5)

img.brightness(value)

Adjusts image brightness. Positive values brighten, negative values darken.

Parameters

value : Int - Brightness adjustment

img.contrast(value)

Adjusts image contrast. Positive increases contrast, negative decreases.

Parameters

value : Float or Int - Contrast adjustment

img.hue_rotate(degrees)

Rotates the hue of all pixels by the given number of degrees.

Parameters

degrees : Int - Hue rotation in degrees

let adjusted = Image.new("photo.jpg")
    .brightness(20)
    .contrast(1.5)
    .hue_rotate(90)
adjusted.to_file("adjusted.jpg")

Output Settings

img.quality(n)

Sets the output quality for JPEG encoding. Default is 85.

Parameters

n : Int - Quality from 1 (smallest) to 100 (best)

img.format(fmt)

Sets the output format explicitly.

Parameters

fmt : String - One of: "jpeg", "png", "gif", "bmp", "ico", "tiff", "webp"

# Convert PNG to JPEG at 70% quality
let img = Image.new("photo.png")
    .format("jpeg")
    .quality(70)
img.to_file("photo.jpg")

Saving & Exporting

img.to_file(path)

Saves the image to a file. Format is determined by: .format() setting, then file extension, then PNG fallback.

Parameters

path : String - Output file path

Returns

Boolean - true on success

Image.new("photo.jpg").thumbnail(200).to_file("thumb.jpg")

img.to_buffer()

Encodes the image to a base64 string. Useful for storing in databases, HTTP responses, or passing to S3.

Returns

String - Base64-encoded image data

let img = Image.new("photo.jpg").thumbnail(100)
let base64_data = img.to_buffer()

# Store in S3
S3.put_object("my-bucket", "thumb.jpg", base64_data, {
    "content_type": "image/jpeg"
})

Complete Examples

Thumbnail generation in a controller

fn upload(req)
    let file = req.files["avatar"]
    let img = Image.from_buffer(file.data)

    # Create multiple sizes
    let large = img.resize(800, 800)
    let medium = img.thumbnail(400)
    let small = img.thumbnail(100)

    large.to_file("public/uploads/avatar_large.jpg")
    medium.to_file("public/uploads/avatar_medium.jpg")
    small.to_file("public/uploads/avatar_small.jpg")

    return { "status": 200, "body": "Upload complete" }
end

Image processing pipeline

let img = Image.new("raw_photo.jpg")
    .resize(1200, 900)
    .brightness(10)
    .contrast(1.2)
    .quality(85)

img.to_file("processed.jpg")

# Also create a grayscale thumbnail
img.grayscale().thumbnail(200).to_file("thumb_gray.jpg")

Format conversion with S3

# Convert all PNGs to WebP
let files = S3.list_objects("images", "photos/")
for file in files
    if file.ends_with(".png")
        let data = S3.get_object("images", file)
        let img = Image.from_buffer(data)
            .format("webp")
            .quality(80)
        let new_key = file.replace(".png", ".webp")
        S3.put_object("images", new_key, img.to_buffer(), {
            "content_type": "image/webp"
        })
    end
end