Image Tools

fogleman/primitive: Reproducing images with geometric primitives.
Bigjpg - AI 人工智能图片无损放大 - 使用人工智能深度卷积神经网络(CNN)无损放大图片
 分享 3 款图片处理神器，渣图还原大法好，老厉害了！ - 知乎
 LunaPic | Free Online Photo Editor | Transparent Background
picthing - manage your pictures better

ImageMagick

Tool	Description
`animate`	animate an image sequence on any X server.
`compare`	mathematically and visually annotate the difference between an image and its reconstruction.
`composite`	overlap one image over another.
`conjure`	interpret and execute scripts written in the Magick Scripting Language (MSL).
`convert`	convert between image formats as well as resize an image, blur, crop, despeckle, dither, draw on, flip, join, re-sample, and much more.
`display`	display an image or image sequence on any X server.
`identify`	describe the format and characteristics of one or more image files.
`import`	save any visible window on an X server and outputs it as an image file. You can capture a single window, the entire screen, or any rectangular portion of the screen.
`mogrify`	resize an image, blur, crop, despeckle, dither, draw on, flip, join, re-sample, and much more. `mogrify` overwrites the original image file, whereas, `convert` writes to a different image file.
`montage`	create a composite image by combining several separate images. The images are tiled on the composite image optionally adorned with a border, frame, image name, and more.
`stream`	a lightweight tool to stream one or more pixel components of the image or portion of the image to your choice of storage formats. It writes the pixel components as they are read from the input image a row at a time making stream desirable when working with large images or when you require raw pixel components.

TODO: ImageMagick v7 deprecated convert command, use magick instead.
The above standalone comamnds became magick's sub-command
And magick is more strict about command line syntax

ImageMagick v7 Examples
Command-line Tools @ ImageMagick
ImageMagick – Command-line Processing
ImageMagick: Convert, Edit, Or Compose Bitmap Images

ImageMagick 使用心得
 Turn many pictures into a movie | daniel.haxx.se

The Definitive Guide to ImageMagick | Michael Still | Apress author's site

# crop lower part of image
convert input.jpg -crop 300x150+0+150 +repage image-cropped.jpg

# add shadow
convert screenshot.jpg \( +clone -background black -shadow 60×5+0+5 \) +swap -background white -layers merge +repage shadow.jpg

# add timestamp, http://www.imagemagick.org/script/escape.php
convert *.jpg -font Arial -pointsize 72 -gravity SouthEast -fill yellow -annotate +100+100 %[exif:datetime] output-%d.jpg

# convert to pdf
convert a.png b.png -compress jpeg -resize 1240x1753 \
                      -extent 1240x1753 -gravity center \
                      -unis PixelsPerInch -density 150x150 multipage.pdf

# convert sequence of images to GIF
convert -delay '1x20' *.png output.gif # 20FPS
convert -delay '2x1' *.png output.gif  # 2 sec each frame

Watermark

imagemagick - Apply watermark with text / image using GraphicsMagick - Stack Overflow

convert -background transparent -fill grey -font Calibri -size 140x80 -pointsize 14 -gravity southeast label:'copyright text' output.png

Resizing Image

Resizing or Scaling -- ImageMagick Examples

# resizing image
convert -resize 300x300 image.jpg image-small.jpg
convert -resize 1080 {from_path} {to_path}  # fix weight only
convert -resize x1080 {from_path} {to_path}  # fix height only

# very low quality
convert -thumbnail {width} *.jpg

# resize to max width 1920
mogrify -resize 1920x\> input_folder/*.jpg -path output_folder/

How can I scale all images in a folder to the same width? - Ask Ubuntu

Command-line Processing Geometry @ ImageMagick

My favorite Linux commands for optimizing web images | Opensource.com with mogrify

Image stitching

# horizontal
magick image.jpg ...  +append output.jpg
# vertical
magick image.jpg ...  -append output.jpg

creating image

Canvas Creation: Random -- IM v7 Examples
Canvas Creation: Tile -- IM v7 Examples

# solid color image
magick -size 100x100 canvas:khaki canvas_khaki.gif
magick -size 100x100 xc:wheat  canvas_wheat.gif

# patterned image
# use "tile" to take source from pipe and repeat
convert -size 30x54 pattern:hexagons \
          -fill tomato     -opaque white \
          -fill dodgerblue -draw 'color 10,10 floodfill' \
          -fill limegreen  -draw 'color 10,25 floodfill' \
          -roll +15+27 \
          -fill dodgerblue -draw 'color 10,10 floodfill' \
          -fill limegreen  -draw 'color 10,25 floodfill'   miff:- |\
magick -size 200x200 tile:- image.jpg

magick -size 500x500 pattern:checkerboard  miff:- |\
magick -size 5000x5000 tile:- image.jpg

# get quality of JPEG file
magick identify -verbose file.jpg | grep Quality

with text

magick -size 1280x720 xc:grey \
          -font roboto -pointsize 300 -draw "text 100,600 'userName' text 100,300 'userTitle'"  \
          image.jpg

magick -size 1280x720 xc:grey \
          \( -background none label:"A very much longer label" -trim -gravity center \) \
          -composite image.jpg

# add overlay text
magick image.jpg \
          \( -size 560x230 -background white -font roboto-mono label:"0001" -trim -gravity center -extent 560x230 \) \
          -gravity northwest -geometry +1100+15 -composite image1.jpg

dynamic - ImageMagick best fit text within rectangle? - Stack Overflow

Colorspace

Color Management @ ImageMagick
Converting anything to RGB correctly - ImageMagick

magick image.jpg \
 CMYK.jpg -profile /usr/share/color/icc/colord/sRGB.icc RGB.jpg

magick flower_original.jpeg -colorspace Gray greyscale_flower.jpeg
magick -list colorspace
magick flower_original.jpeg -negate flower_negative.jpeg

Photon

Photon: A WebAssembly Image Processing Library

Node.js

sharp - High performance Node.js image processing is VIPS's Node binding
lovell/sharp: High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP, AVIF and TIFF images. Uses the libvips library.
How To Process Images in Node.js with Sharp | DigitalOcean

jimp-dev/jimp: An image processing library written entirely in JavaScript for Node, with zero external or native dependencies.

Python

Wand documentation
ImageMagick/PythonMagick: PythonMagick
python - Documents and examples of PythonMagick - Stack Overflow

Python Imaging Library (PIL)
Pillow — Pillow (PIL Fork) documentation
python-image of most distro points to pillow
Image Module — Pillow (PIL Fork) documentation
Concepts — Pillow (PIL Fork) documentation

Imageio website

OpenStitching/stitching: A Python package for fast and robust Image Stitching