Image Processing
ImageMagick
ImageMagick - convert CLI tool
Version: ImageMagick 6.9.12-93 Q16 x86_64 17898 https://legacy.imagemagick.org
Copyright: (C) 1999 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC Modules OpenMP(4.5)
Delegates (built-in): bzlib cairo djvu fontconfig freetype gslib gvc jbig jng jp2 jpeg lcms lqr ltdl lzma openexr pangocairo png ps raqm raw rsvg tiff webp wmf x xml zlib
Usage: convert [options ...] file [ [options ...] file ...] [options ...] file
Image Settings:
-adjoin join images into a single multi-image file
-affine matrix affine transform matrix
-alpha option activate, deactivate, reset, or set the alpha channel
-antialias remove pixel-aliasing
-authenticate password
decipher image with this password
-attenuate value lessen (or intensify) when adding noise to an image
-background color background color
-bias value add bias when convolving an image
-black-point-compensation
use black point compensation
-blue-primary point chromaticity blue primary point
-bordercolor color border color
-caption string assign a caption to an image
-channel type apply option to select image channels
-clip-mask filename associate a clip mask with the image
-colors value preferred number of colors in the image
-colorspace type alternate image colorspace
-comment string annotate image with comment
-compose operator set image composite operator
-compress type type of pixel compression when writing the image
-define format:option
define one or more image format options
-delay value display the next image after pausing
-density geometry horizontal and vertical density of the image
-depth value image depth
-direction type render text right-to-left or left-to-right
-display server get image or font from this X server
-dispose method layer disposal method
-dither method apply error diffusion to image
-encoding type text encoding type
-endian type endianness (MSB or LSB) of the image
-family name render text with this font family
-fill color color to use when filling a graphic primitive
-filter type use this filter when resizing an image
-font name render text with this font
-format "string" output formatted image characteristics
-fuzz distance colors within this distance are considered equal
-gravity type horizontal and vertical text placement
-green-primary point chromaticity green primary point
-intensity method method to generate intensity value from pixel
-intent type type of rendering intent when managing the image color
-interlace type type of image interlacing scheme
-interline-spacing value
set the space between two text lines
-interpolate method pixel color interpolation method
-interword-spacing value
set the space between two words
-kerning value set the space between two letters
-label string assign a label to an image
-limit type value pixel cache resource limit
-loop iterations add Netscape loop extension to your GIF animation
-mask filename associate a mask with the image
-matte store matte channel if the image has one
-mattecolor color frame color
-moments report image moments
-monitor monitor progress
-orient type image orientation
-page geometry size and location of an image canvas (setting)
-ping efficiently determine image attributes
-pointsize value font point size
-precision value maximum number of significant digits to print
-preview type image preview type
-quality value JPEG/MIFF/PNG compression level
-quiet suppress all warning messages
-red-primary point chromaticity red primary point
-regard-warnings pay attention to warning messages
-remap filename transform image colors to match this set of colors
-repage geometry size and location of an image canvas
-respect-parentheses settings remain in effect until parenthesis boundary
-sampling-factor geometry
horizontal and vertical sampling factor
-scene value image scene number
-seed value seed a new sequence of pseudo-random numbers
-size geometry width and height of image
-stretch type render text with this font stretch
-stroke color graphic primitive stroke color
-strokewidth value graphic primitive stroke width
-style type render text with this font style
-support factor resize support: > 1.0 is blurry, < 1.0 is sharp
-synchronize synchronize image to storage device
-taint declare the image as modified
-texture filename name of texture to tile onto the image background
-tile-offset geometry
tile offset
-treedepth value color tree depth
-transparent-color color
transparent color
-undercolor color annotation bounding box color
-units type the units of image resolution
-verbose print detailed information about the image
-view FlashPix viewing transforms
-virtual-pixel method
virtual pixel access method
-weight type render text with this font weight
-white-point point chromaticity white point
Image Operators:
-adaptive-blur geometry
adaptively blur pixels; decrease effect near edges
-adaptive-resize geometry
adaptively resize image using 'mesh' interpolation
-adaptive-sharpen geometry
adaptively sharpen pixels; increase effect near edges
-alpha option on, activate, off, deactivate, set, opaque, copy
transparent, extract, background, or shape
-annotate geometry text
annotate the image with text
-auto-gamma automagically adjust gamma level of image
-auto-level automagically adjust color levels of image
-auto-orient automagically orient (rotate) image
-bench iterations measure performance
-black-threshold value
force all pixels below the threshold into black
-blue-shift factor simulate a scene at nighttime in the moonlight
-blur geometry reduce image noise and reduce detail levels
-border geometry surround image with a border of color
-bordercolor color border color
-brightness-contrast geometry
improve brightness / contrast of the image
-canny geometry detect edges in the image
-cdl filename color correct with a color decision list
-charcoal radius simulate a charcoal drawing
-chop geometry remove pixels from the image interior
-clamp keep pixel values in range (0-QuantumRange)
-clip clip along the first path from the 8BIM profile
-clip-path id clip along a named path from the 8BIM profile
-colorize value colorize the image with the fill color
-color-matrix matrix apply color correction to the image
-connected-components connectivity
connected-components uniquely labeled
-contrast enhance or reduce the image contrast
-contrast-stretch geometry
improve contrast by 'stretching' the intensity range
-convolve coefficients
apply a convolution kernel to the image
-cycle amount cycle the image colormap
-decipher filename convert cipher pixels to plain pixels
-deskew threshold straighten an image
-despeckle reduce the speckles within an image
-distort method args
distort images according to given method ad args
-draw string annotate the image with a graphic primitive
-edge radius apply a filter to detect edges in the image
-encipher filename convert plain pixels to cipher pixels
-emboss radius emboss an image
-enhance apply a digital filter to enhance a noisy image
-equalize perform histogram equalization to an image
-evaluate operator value
evaluate an arithmetic, relational, or logical expression
-extent geometry set the image size
-extract geometry extract area from image
-features distance analyze image features (e.g. contrast, correlation)
-fft implements the discrete Fourier transform (DFT)
-flip flip image vertically
-floodfill geometry color
floodfill the image with color
-flop flop image horizontally
-frame geometry surround image with an ornamental border
-function name parameters
apply function over image values
-gamma value level of gamma correction
-gaussian-blur geometry
reduce image noise and reduce detail levels
-geometry geometry preferred size or location of the image
-grayscale method convert image to grayscale
-hough-lines geometry
identify lines in the image
-identify identify the format and characteristics of the image
-ift implements the inverse discrete Fourier transform (DFT)
-implode amount implode image pixels about the center
-interpolative-resize geometry
resize image using 'point sampled' interpolation
-kuwahara geometry edge preserving noise reduction filter
-lat geometry local adaptive thresholding
-level value adjust the level of image contrast
-level-colors color,color
level image with the given colors
-linear-stretch geometry
improve contrast by 'stretching with saturation'
-liquid-rescale geometry
rescale image with seam-carving
-local-contrast geometry
enhance local contrast
-magnify double the size of the image with pixel art scaling
-mean-shift geometry delineate arbitrarily shaped clusters in the image
-median geometry apply a median filter to the image
-mode geometry make each pixel the 'predominant color' of the
neighborhood
-modulate value vary the brightness, saturation, and hue
-monochrome transform image to black and white
-morphology method kernel
apply a morphology method to the image
-motion-blur geometry
simulate motion blur
-negate replace every pixel with its complementary color
-noise geometry add or reduce noise in an image
-normalize transform image to span the full range of colors
-opaque color change this color to the fill color
-ordered-dither NxN
add a noise pattern to the image with specific
amplitudes
-paint radius simulate an oil painting
-perceptible epsilon
pixel value less than |epsilon| become epsilon or
-epsilon
-polaroid angle simulate a Polaroid picture
-posterize levels reduce the image to a limited number of color levels
-profile filename add, delete, or apply an image profile
-quantize colorspace reduce colors in this colorspace
-radial-blur angle radial blur the image (deprecated use -rotational-blur
-raise value lighten/darken image edges to create a 3-D effect
-random-threshold low,high
random threshold the image
-region geometry apply options to a portion of the image
-render render vector graphics
-resample geometry change the resolution of an image
-resize geometry resize the image
-roll geometry roll an image vertically or horizontally
-rotate degrees apply Paeth rotation to the image
-rotational-blur angle
rotational blur the image
-sample geometry scale image with pixel sampling
-scale geometry scale the image
-segment values segment an image
-selective-blur geometry
selectively blur pixels within a contrast threshold
-sepia-tone threshold
simulate a sepia-toned photo
-set property value set an image property
-shade degrees shade the image using a distant light source
-shadow geometry simulate an image shadow
-sharpen geometry sharpen the image
-shave geometry shave pixels from the image edges
-shear geometry slide one edge of the image along the X or Y axis
-sigmoidal-contrast geometry
increase the contrast without saturating highlights or
shadows
-sketch geometry simulate a pencil sketch
-solarize threshold negate all pixels above the threshold level
-sparse-color method args
fill in a image based on a few color points
-splice geometry splice the background color into the image
-spread radius displace image pixels by a random amount
-statistic type geometry
replace each pixel with corresponding statistic from the
neighborhood
-strip strip image of all profiles and comments
-swirl degrees swirl image pixels about the center
-threshold value threshold the image
-thumbnail geometry create a thumbnail of the image
-tile filename tile image when filling a graphic primitive
-tint value tint the image with the fill color
-transform affine transform image
-transparent color make this color transparent within the image
-transpose flip image vertically and rotate 90 degrees
-transverse flop image horizontally and rotate 270 degrees
-trim trim image edges
-type type image type
-unique-colors discard all but one of any pixel color
-unsharp geometry sharpen the image
-vignette geometry soften the edges of the image in vignette style
-wave geometry alter an image along a sine wave
-wavelet-denoise threshold
removes noise from the image using a wavelet transform
-white-threshold value
force all pixels above the threshold into white
Image Sequence Operators:
-append append an image sequence
-clut apply a color lookup table to the image
-coalesce merge a sequence of images
-combine combine a sequence of images
-compare mathematically and visually annotate the difference between an image and its reconstruction
-complex operator perform complex mathematics on an image sequence
-composite composite image
-copy geometry offset
copy pixels from one area of an image to another
-crop geometry cut out a rectangular region of the image
-deconstruct break down an image sequence into constituent parts
-evaluate-sequence operator
evaluate an arithmetic, relational, or logical expression
-flatten flatten a sequence of images
-fx expression apply mathematical expression to an image channel(s)
-hald-clut apply a Hald color lookup table to the image
-layers method optimize, merge, or compare image layers
-morph value morph an image sequence
-mosaic create a mosaic from an image sequence
-poly terms build a polynomial from the image sequence and the corresponding
terms (coefficients and degree pairs).
-print string interpret string and print to console
-process arguments process the image with a custom image filter
-separate separate an image channel into a grayscale image
-smush geometry smush an image sequence together
-write filename write images to this file
Image Stack Operators:
-clone indexes clone an image
-delete indexes delete the image from the image sequence
-duplicate count,indexes
duplicate an image one or more times
-insert index insert last image into the image sequence
-reverse reverse image sequence
-swap indexes swap two images in the image sequence
Miscellaneous Options:
-debug events display copious debugging information
-distribute-cache port
distributed pixel cache spanning one or more servers
-help print program options
-list type print a list of supported option arguments
-log format format of debugging information
-version print version information
By default, the image format of `file' is determined by its magic
number. To specify a particular image format, precede the filename
with an image format name and a colon (i.e. ps:image) or specify the
image type as the filename suffix (i.e. image.ps). Specify 'file' as
'-' for standard input or output.
ImageMagick - Resize image to a specific width and height
convert $input_image -resize 800x600 $output_image
ImageMagick - Crop image to a specific width and height
convert $input_image -crop ${width}x${height}+${x}+${y} $output_image
ImageMagick - Compress image to a specific quality
convert $input_image -quality $quality $output_image
ExifTool
ExifTool - Remove all metadata from the given image
exiftool -all= $image_file
AVIF
-
Tutorial
-
avifenc
Syntax: avifenc [options] input.[jpg|jpeg|png|y4m] output.avif Standard options: -h,--help : Show syntax help (this page) -V,--version : Show the version number Basic options: -q,--qcolor Q : Set quality for color (0-100, where 100 is lossless) --qalpha Q : Set quality for alpha (0-100, where 100 is lossless) -s,--speed S : Encoder speed (0-10, slowest-fastest, 'default' or 'd' for codec internal defaults. default speed: 6) Advanced options: -j,--jobs J : Number of jobs (worker threads, default: 1. Use "all" to use all available cores) --no-overwrite : Never overwrite existing output file -o,--output FILENAME : Instead of using the last filename given as output, use this filename -l,--lossless : Set all defaults to encode losslessly, and emit warnings when settings/input do not allow for it -d,--depth D : Output depth [8,10,12]. (JPEG/PNG only; For y4m or stdin, depth is retained) -y,--yuv FORMAT : Output format [default=auto, 444, 422, 420, 400]. Ignored for y4m or stdin (y4m format is retained) For JPEG, auto honors the JPEG's internal format, if possible. For all other cases, auto defaults to 444 -p,--premultiply : Premultiply color by the alpha channel and signal this in the AVIF --sharpyuv : Use sharp RGB to YUV420 conversion (if supported). Ignored for y4m or if output is not 420. --stdin : Read y4m frames from stdin instead of files; no input filenames allowed, must set before offering output filename --cicp,--nclx P/T/M : Set CICP values (nclx colr box) (3 raw numbers, use -r to set range flag) P = color primaries T = transfer characteristics M = matrix coefficients (use 2 for any you wish to leave unspecified) -r,--range RANGE : YUV range [limited or l, full or f]. (JPEG/PNG only, default: full; For y4m or stdin, range is retained) --tilerowslog2 R : Set log2 of number of tile rows (0-6, default: 0) --tilecolslog2 C : Set log2 of number of tile columns (0-6, default: 0) --autotiling : Set --tilerowslog2 and --tilecolslog2 automatically -g,--grid MxN : Encode a single-image grid AVIF with M cols & N rows. Either supply MxN identical W/H/D images, or a single image that can be evenly split into the MxN grid and follow AVIF grid image restrictions. The grid will adopt the color profile of the first image supplied. -c,--codec C : AV1 codec to use (choose from versions list below) --exif FILENAME : Provide an Exif metadata payload to be associated with the primary item (implies --ignore-exif) --xmp FILENAME : Provide an XMP metadata payload to be associated with the primary item (implies --ignore-xmp) --icc FILENAME : Provide an ICC profile payload to be associated with the primary item (implies --ignore-icc) -a,--advanced KEY[=VALUE] : Pass an advanced, codec-specific key/value string pair directly to the codec. avifenc will warn on any not used by the codec. --duration D : Set all following frame durations (in timescales) to D; default 1. Can be set multiple times (before supplying each filename) --timescale,--fps V : Set the timescale to V. If all frames are 1 timescale in length, this is equivalent to frames per second (Default: 30) If neither duration nor timescale are set, avifenc will attempt to use the framerate stored in a y4m header, if present. -k,--keyframe INTERVAL : Set the maximum keyframe interval (any set of INTERVAL consecutive frames will have at least one keyframe). Set to 0 to disable (default). --ignore-exif : If the input file contains embedded Exif metadata, ignore it (no-op if absent) --ignore-xmp : If the input file contains embedded XMP metadata, ignore it (no-op if absent) --ignore-profile,--ignore-icc : If the input file contains an embedded color profile, ignore it (no-op if absent) --pasp H,V : Add pasp property (aspect ratio). H=horizontal spacing, V=vertical spacing --crop CROPX,CROPY,CROPW,CROPH : Add clap property (clean aperture), but calculated from a crop rectangle --clap WN,WD,HN,HD,HON,HOD,VON,VOD: Add clap property (clean aperture). Width, Height, HOffset, VOffset (in num/denom pairs) --irot ANGLE : Add irot property (rotation). [0-3], makes (90 * ANGLE) degree rotation anti-clockwise --imir AXIS : Add imir property (mirroring). 0=top-to-bottom, 1=left-to-right --clli MaxCLL,MaxPALL : Add clli property (content light level information). --repetition-count N or infinite : Number of times an animated image sequence will be repeated. Use 'infinite' for infinite repetitions (Default: infinite) --min QP : Set min quantizer for color (0-63, where 0 is lossless) --max QP : Set max quantizer for color (0-63, where 0 is lossless) --minalpha QP : Set min quantizer for alpha (0-63, where 0 is lossless) --maxalpha QP : Set max quantizer for alpha (0-63, where 0 is lossless) --target-size S : Set target file size in bytes (up to 7 times slower) --progressive : EXPERIMENTAL: Encode a progressive image -- : Signals the end of options. Everything after this is interpreted as file names. aom-specific advanced options: 1. <key>=<value> applies to both the color (YUV) planes and the alpha plane (if present). 2. color:<key>=<value> or c:<key>=<value> applies only to the color (YUV) planes. 3. alpha:<key>=<value> or a:<key>=<value> applies only to the alpha plane (if present). Since the alpha plane is encoded as a monochrome image, the options that refer to the chroma planes, such as enable-chroma-deltaq=B, should not be used with the alpha plane. In addition, the film grain options are unlikely to make sense for the alpha plane. When used with libaom 3.0.0 or later, any key-value pairs supported by the aom_codec_set_option() function can be used. When used with libaom 2.0.x or older, the following key-value pairs can be used: aq-mode=M : Adaptive quantization mode (0: off (default), 1: variance, 2: complexity, 3: cyclic refresh) cq-level=Q : Constant/Constrained Quality level (0-63, end-usage must be set to cq or q) enable-chroma-deltaq=B : Enable delta quantization in chroma planes (0: disable (default), 1: enable) end-usage=MODE : Rate control mode (vbr, cbr, cq, or q) sharpness=S : Bias towards block sharpness in rate-distortion optimization of transform coefficients (0-7, default: 0) tune=METRIC : Tune the encoder for distortion metric (psnr or ssim, default: psnr) film-grain-test=TEST : Film grain test vectors (0: none (default), 1: test-1 2: test-2, ... 16: test-16) film-grain-table=FILENAME : Path to file containing film grain parameters Version: 1.0.4 (dav1d [dec]:1.2.1-0-g8a6f054, aom [enc]:3.6.1) libyuv : available (1864)
Convert image to AVIF in batch
convert_to_avif() {
local dry_run=0;
local ext="$1";
if [ "$2" = "-n" ]; then
dry_run=1;
fi
[ -z "$ext" ] && echo "Usage: convert_to_avif <ext> [-n]" && return 1;
find . -type f -iname "*.$ext" -print0 | while IFS= read -r -d '' f; do
if [ $dry_run -eq 0 ]; then
avifenc \
--speed 3 \
--jobs 8 \
-a end-usage=q \
-a cq-level=18 \
-a "color:cq-level=18" \
"$f" "${f%.*}.avif"
else
echo "$f"
fi
done
}