Initial commit

.editorconfig

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+root = true
+
+[*.cr]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true

.github/workflows/ci.yml

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+name: crystal-vips CI
+on:
+  push:
+  pull_request:
+    branches: [main]
+  schedule:
+    - cron: '0 6 * * 6'  # Every Saturday 6 AM
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download source
+        uses: actions/checkout@v2
+      - name: Install Crystal
+        uses: crystal-lang/install-crystal@v1
+      - name: Install libvips
+        env:
+          DEBIAN_FRONTEND: noninteractive
+        run:
+          # we only need the library
+          sudo apt-get install --fix-missing -qq -o Acquire::Retries=3 libvips-dev
+      - name: Run tests
+        run: crystal spec
+      - name: Check formatting
+        run: crystal tool format --check

.github/workflows/doc.yml

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+name: Deploy Docs
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download source
+        uses: actions/checkout@v2
+      - name: Install Crystal
+        uses: crystal-lang/install-crystal@v1
+      - name: Build
+        run: crystal docs
+      - name: Deploy
+        if: github.ref == 'refs/heads/main'
+        uses: JamesIves/[email protected]
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          BRANCH: gh-pages
+          FOLDER: docs
+          CLEAN: true

.gitignore

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+/docs/
+/lib/
+/bin/
+/images/
+/.shards/
+*.dwarf
+.vscode/**
+# Libraries don't need dependency lock
+# Dependencies will be locked in applications that use them
+/shard.lock

LICENSE

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+MIT License
+
+Copyright (c) 2022 Ali Naqvi <[email protected]>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# CrystalVips
+
+[![crystal-vips CI](https://github.com/naqvis/crystal-vips/actions/workflows/ci.yml/badge.svg)](https://github.com/naqvis/crystal-vips/actions/workflows/ci.yml)
+[![Latest release](https://img.shields.io/github/release/naqvis/crystal-vips.svg)](https://github.com/naqvis/crystal-vips/releases)
+[![Docs](https://img.shields.io/badge/docs-available-brightgreen.svg)](https://naqvis.github.io/crystal-vips/)
+
+Provides Crystal language interface to the [libvips](https://github.com/libvips/libvips) image processing library.
+Programs that use `CrystalVips` don't manipulate images directly, instead they create pipelines of image processing operations starting from a source image. When the pipe is connected to a destination, the whole pipeline executes at once and in parallel, streaming the image from source to destination in a set of small fragments.
+
+Because `CrystalVips` is parallel, its' quick, and because it doesn't need to keep entire images in memory, its light. For example, the libvips speed and memory use benchmark:
+
+[https://github.com/libvips/libvips/wiki/Speed-and-memory-use](https://github.com/libvips/libvips/wiki/Speed-and-memory-use)
+
+## Pre-requisites
+
+You need to [install the libvips
+library](https://www.libvips.org/install.html). It's in the linux package managers, homebrew and MacPorts, and there are Windows binaries on the vips website. For example, on Debian:
+
+```
+sudo apt-get install --no-install-recommends libvips42
+```
+
+(`--no-install-recommends` stops Debian installing a *lot* of extra packages)
+
+Or macOS:
+
+```
+brew install vips
+```
+
+## Installation
+
+1. Add the dependency to your `shard.yml`:
+
+   ```yaml
+   dependencies:
+     vips:
+       github: naqvis/crystal-vips
+   ```
+
+2. Run `shards install`
+
+## Usage
+
+```crystal
+require "vips"
+
+im = Vips::Image.new_from_file("image.jpg")
+
+# put im at position (100, 100) in a 3000 x 3000 pixel image, 
+# make the other pixels in the image by mirroring im up / down / 
+# left / right, see
+# https://libvips.github.io/libvips/API/current/libvips-conversion.html#vips-embed
+im = im.embed(100, 100, 3000, 3000, extend: Vips::Enums::Extend::Mirror)
+
+# multiply the green (middle) band by 2, leave the other two alone
+im *= [1, 2, 1]
+
+# make an image from an array constant, convolve with it
+mask = Vips::Image.new_from_array([
+    [-1, -1, -1],
+    [-1, 16, -1],
+    [-1, -1, -1]], 8)
+im = im.conv(mask, precision: Vips::Enums::Precision::Integer)
+
+# finally, write the result back to a file on disk
+im.write_to_file("output.jpg")
+```
+
+Refer to [samples](samples) folder for more samples
+
+## Development
+
+To run all tests:
+
+```
+crystal spec
+```
+
+# Getting more help
+
+The libvips website has a handy table of [all the libvips
+operators](http://libvips.github.io/libvips/API/current/func-list.html). Each
+one links to the main API docs so you can see what you need to pass to it.
+
+A simple way to see the arguments for an operation is to try running it
+from the command-line. For example:
+
+```bash
+$ vips embed
+embed an image in a larger image
+usage:
+   embed in out x y width height
+where:
+   in           - Input image, input VipsImage
+   out          - Output image, output VipsImage
+   x            - Left edge of input in output, input gint
+			default: 0
+			min: -1000000000, max: 1000000000
+   y            - Top edge of input in output, input gint
+			default: 0
+			min: -1000000000, max: 1000000000
+   width        - Image width in pixels, input gint
+			default: 1
+			min: 1, max: 1000000000
+   height       - Image height in pixels, input gint
+			default: 1
+			min: 1, max: 1000000000
+optional arguments:
+   extend       - How to generate the extra pixels, input VipsExtend
+			default: black
+			allowed: black, copy, repeat, mirror, white, background
+   background   - Color for background pixels, input VipsArrayDouble
+operation flags: sequential 
+```
+
+## Contributing
+
+1. Fork it (<https://github.com/naqvis/crystal-vips/fork>)
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create a new Pull Request
+
+## Contributors
+
+- [Ali Naqvi](https://github.com/naqvis) - creator and maintainer

example/annotate.cr

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+require "../src/vips"
+
+if ARGV.size < 2
+  puts "Usage: #{__FILE__} input_image output"
+  exit(1)
+end
+
+im = Vips::Image.new_from_file(ARGV[0], access: Vips::Enums::Access::Sequential)
+
+left_text, _ = Vips::Image.text("left corner", dpi: 300)
+left = left_text.embed(50, 50, im.width, 150)
+
+right_text, _ = Vips::Image.text("right corner", dpi: 300)
+right = right_text.embed(im.width - right_text.width - 50, 50, im.width, 150)
+
+footer = (left | right).ifthenelse(0, [255, 0, 0], blend: true)
+
+im = im.insert(footer, 0, im.height, expand: true)
+
+im.write_to_file ARGV[1]

example/canny.cr

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+require "../src/vips"
+
+# Edge detection
+
+if ARGV.size < 2
+  puts "Usage: #{__FILE__} input_image output"
+  exit(1)
+end
+
+im = Vips::Image.new_from_file(ARGV[0], access: Vips::Enums::Access::Sequential)
+
+# optionall convert to greyscale
+# mono = im.colourspace(Vips::Enums::Interpretation::Bw)
+# canny = mono.canny(sigma: 1.4, precision: Vips::Enums::Precision::Integer)
+
+# Canny edge detector
+canny = im.canny(sigma: 1.4, precision: Vips::Enums::Precision::Integer)
+
+# Canny makes a float image, scale the output up to make it visible
+scale = canny * 64
+
+scale.write_to_file(ARGV[1])

example/captcha_generator.cr

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+require "../src/vips"
+
+# Captcha generator
+# Reference: https://github.com/libvips/libvips/issues/898
+
+def wobble(image)
+  # a warp image is a 2D grid containing the new coordinates of each pixel with
+  # the new x in band 0 and the new y in band 1
+  #
+  # you can also use a complex image
+  #
+  # start from a low-res XY image and distort it
+
+  xy = Vips::Image.xyz(image.width // 20, image.height // 20)
+  x_distort = Vips::Image.gaussnoise(xy.width, xy.height)
+  y_distort = Vips::Image.gaussnoise(xy.width, xy.height)
+  xy += (x_distort.bandjoin(y_distort) / 150)
+  xy = xy.resize(20)
+  xy *= 20
+
+  # apply the warp
+  image.mapim(xy)
+end
+
+if ARGV.size < 2
+  puts "Usage: #{__FILE__} outputfile text"
+  exit(1)
+end
+
+text_layer = Vips::Image.black 1, 1
+x_position = 0
+
+ARGV[1].each_char do |c|
+  if c.ascii_whitespace?
+    x_position += 50
+    next
+  end
+
+  letter, _ = Vips::Image.text(c.to_s, dpi: 600)
+
+  image = letter.gravity(Vips::Enums::CompassDirection::Centre, letter.width + 50, letter.height + 50)
+
+  # random scale and rotate
+  image = image.similarity(scale: Random.rand(0.2) + 0.8,
+    angle: Random.rand(40) - 20)
+
+  # random wobble
+  image = wobble(image)
+
+  # random color
+  color = (1..3).map { Random.rand(255) }
+  image = image.ifthenelse(color, 0, true)
+
+  # tag as 9-bit srgb
+  image = image.copy(interpretation: Vips::Enums::Interpretation::Srgb).cast(Vips::Enums::BandFormat::Uchar)
+
+  # position at our write position in the image
+  image = image.embed(x_position, 0, image.width + x_position, image.height)
+
+  text_layer += image
+  text_layer = text_layer.cast(Vips::Enums::BandFormat::Uchar)
+
+  x_position += letter.width
+end
+
+# remove any unused edges
+text_layer = text_layer.crop(*text_layer.find_trim(background: 0))
+
+# make an alpha for the text layer: just a mono version of the image, but scaled
+# up so letters themeselves are not transparent
+alpha = (text_layer.colourspace(Vips::Enums::Interpretation::Bw) * 3).cast(Vips::Enums::BandFormat::Uchar)
+text_layer = text_layer.bandjoin(alpha)
+
+# make a white background with random speckles
+speckles = Vips::Image.gaussnoise(text_layer.width, text_layer.height, mean: 400, sigma: 200)
+background = (1..3).reduce(speckles) do |a, _|
+  a.bandjoin(Vips::Image.gaussnoise(text_layer.width, text_layer.height, mean: 400, sigma: 200))
+    .copy(interpretation: Vips::Enums::Interpretation::Srgb).cast(Vips::Enums::BandFormat::Uchar)
+end
+
+# composite the text over the background
+final = background.composite(text_layer, Vips::Enums::BlendMode::Over)
+final.write_to_file ARGV[0]

example/combine.cr

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+require "../src/vips"
+
+# Conversion
+# Reference: https://github.com/libvips/lua-vips/blob/master/example/combine.lua
+
+if ARGV.size < 3
+  puts "Usage: #{__FILE__} input_image watermark_image output"
+  exit(1)
+end
+
+LEFT = 100
+TOP  = 100
+
+im = Vips::Image.new_from_file(ARGV[0], access: Vips::Enums::Access::Sequential)
+wm = Vips::Image.new_from_file(ARGV[1], access: Vips::Enums::Access::Sequential)
+
+width = wm.width
+height = wm.height
+
+# extract related area from main image
+base = im.crop(LEFT, TOP, width, height)
+
+# composite the two areas using the PDF "over" mode
+composite = base.composite(wm, Vips::Enums::BlendMode::Over)
+
+# the result will have an alpha, and our base image does not .. we must flatten
+# out the alpha before we can insert it back into a plain RGB JPG image
+rgb = composite.flatten
+
+# insert composite back in to main image on related area
+combined = im.insert(rgb, LEFT, TOP)
+combined.write_to_file(ARGV[2])