最近一直在優化我的部落格網站，有常來逛的人應該都可以明顯感受出效能提升，我的其中一個優化項目就是開始使用最新潮的 WebP 與 AVIF 圖檔格式。這篇文章我就來分享如何透過強大的 ImageMagick 工具來批次轉換各種圖片格式。
安裝 ImageMagick 工具
ImageMagick 是一套相當複雜且多功能的工具，且支援各種作業系統平台，無論 Windows, Linux, macOS 通通都有支援，不過安裝的時候確實有些地雷！🔥
我從 ImageMagick 的 Download 頁面的 Linux Binary Release 發現下載的 magick 執行檔並沒有把 heic delegate 編譯進去，所以無法轉換圖片為 AVIF 格式的圖片！ 😒
這是我今天下載最新版的時候看到的版本資訊：
$ magick -version
Version: ImageMagick 7.1.0-57 Q16-HDRI x86_64 d68553b17:20221230 https://imagemagick.org
Copyright: (C) 1999 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC HDRI OpenMP(3.1)
Delegates (built-in): bzlib djvu fontconfig freetype jbig jng jpeg lcms lqr lzma openexr png raqm tiff webp x xml zlib
Compiler: gcc (4.2)
注意: 我在 Ubuntu 22.04.1 LTS (最新穩定版) 透過 apt install imagemagick -y 安裝 ImageMagick 已經有包含 heic 模組了！
不過，你可以改用 imagemagick-docker 專案放在 Docker Hub 上面的 Image (容器映像)，直接透過容器來執行，完全免安裝，這應該是最簡單的使用方法了！👍
除此之外，我在 Windows Binary Release 下載的版本，就真的把所有可能的 Delegates 都加入了，所以直接下載安裝即可，安裝好就可以開始使用了！👍
-
先到 Windows Binary Release 下載最新版安裝檔
以下是自動安裝的命令：
curl -sLO https://imagemagick.org/archive/binaries/ImageMagick-7.1.0-57-Q16-HDRI-x64-dll.exe
.\ImageMagick-7.1.0-57-Q16-HDRI-x64-dll.exe /silent
-
安裝好之後，開啟一個新的命令提示字元(Command Prompt)視窗或 PowerShell 視窗
以下是查詢版本的方式：
magick -version
Version: ImageMagick 7.1.0-57 Q16-HDRI x64 eadf378:20221230 https://imagemagick.org
Copyright: (C) 1999 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC HDRI Modules OpenCL OpenMP(2.0)
Delegates (built-in): bzlib cairo flif freetype gslib heic jng jp2 jpeg jxl lcms lqr lzma openexr pangocairo png ps raqm raw rsvg tiff webp xml zip zlib
Compiler: Visual Studio 2022 (193431937)
如果要看 ImageMagick 所有支援的圖檔格式，可以用以下命令查詢：
magick -list format
點擊看結果 🖱
Format Module Mode Description
-------------------------------------------------------------------------------
3FR DNG r-- Hasselblad CFV/H3D39II (0.21.0-Beta1)
3G2 VIDEO r-- Media Container
3GP VIDEO r-- Media Container
AAI* AAI rw+ AAI Dune image
AI PDF rw- Adobe Illustrator CS2
APNG VIDEO rw+ Animated Portable Network Graphics
ART* ART rw- PFS: 1st Publisher Clip Art
ARW DNG r-- Sony Alpha Raw Image Format (0.21.0-Beta1)
ASHLAR* ASHLAR -w+ Image sequence laid out in continuous irregular courses
AVI VIDEO r-- Microsoft Audio/Visual Interleaved
AVIF HEIC rw+ AV1 Image File Format (1.14.0)
AVS* AVS rw+ AVS X image
BAYER* BAYER rw+ Raw mosaiced samples
BAYERA* BAYER rw+ Raw mosaiced and alpha samples
BGR* BGR rw+ Raw blue, green, and red samples
BGRA* BGR rw+ Raw blue, green, red, and alpha samples
BGRO* BGR rw+ Raw blue, green, red, and opacity samples
BIE* JBIG --- Joint Bi-level Image experts Group interchange format
BMP* BMP rw- Microsoft Windows bitmap image
BMP2* BMP rw- Microsoft Windows bitmap image (V2)
BMP3* BMP rw- Microsoft Windows bitmap image (V3)
BRF* BRAILLE -w- BRF ASCII Braille format
CAL* CALS rw- Continuous Acquisition and Life-cycle Support Type 1
Specified in MIL-R-28002 and MIL-PRF-28002
CALS* CALS rw- Continuous Acquisition and Life-cycle Support Type 1
Specified in MIL-R-28002 and MIL-PRF-28002
CANVAS* XC r-- Constant image uniform color
CAPTION* CAPTION r-- Caption
CIN* CIN rw- Cineon Image File
CIP* CIP -w- Cisco IP phone image format
CLIP* CLIP rw+ Image Clip Mask
CLIPBOARD* CLIPBOARD rw- The system clipboard
CMYK* CMYK rw+ Raw cyan, magenta, yellow, and black samples
CMYKA* CMYK rw+ Raw cyan, magenta, yellow, black, and alpha samples
CR2 DNG r-- Canon Digital Camera Raw Image Format (0.21.0-Beta1)
CR3 DNG r-- Canon Digital Camera Raw Image Format (0.21.0-Beta1)
CRW DNG r-- Canon Digital Camera Raw Image Format (0.21.0-Beta1)
CUBE* CUBE r-- Cube LUT
CUR* ICON rw- Microsoft icon
CUT* CUT r-- DR Halo
DATA* INLINE rw+ Base64-encoded inline images
DCM* DCM r-- Digital Imaging and Communications in Medicine image
DICOM is used by the medical community for images like X-rays. The
specification, "Digital Imaging and Communications in Medicine
(DICOM)", is available at http://medical.nema.org/. In particular,
see part 5 which describes the image encoding (RLE, JPEG, JPEG-LS),
and supplement 61 which adds JPEG-2000 encoding.
DCR DNG r-- Kodak Digital Camera Raw Image File (0.21.0-Beta1)
DCRAW DNG r-- Raw Photo Decoder (dcraw) (0.21.0-Beta1)
DCX* PCX rw+ ZSoft IBM PC multi-page Paintbrush
DDS* DDS rw+ Microsoft DirectDraw Surface
DFONT* TTF r-- Multi-face font package (Freetype 2.12.1)
DJVU* DJVU --- Deja vu
See http://www.djvuzone.org/ for details about the DJVU format. The
DJVU 1.2 specification is available there and at
ftp://swrinde.nde.swri.edu/pub/djvu/documents/.
DNG DNG r-- Digital Negative (0.21.0-Beta1)
DOT DOT --- Graphviz
DPS DPS --- Display Postscript Interpreter
DPX* DPX rw- SMPTE 268M-2003 (DPX 2.0)
Digital Moving Picture Exchange Bitmap, Version 2.0.
See SMPTE 268M-2003 specification at http://www.smtpe.org
DXT1* DDS rw+ Microsoft DirectDraw Surface
DXT5* DDS rw+ Microsoft DirectDraw Surface
EMF EMF r-- Windows Enhanced Meta File
EPDF PDF rw- Encapsulated Portable Document Format
EPI PS rw- Encapsulated PostScript Interchange format
EPS PS rw- Encapsulated PostScript
EPS2 PS2 -w- Level II Encapsulated PostScript
EPS3 PS3 -w+ Level III Encapsulated PostScript
EPSF PS rw- Encapsulated PostScript
EPSI PS rw- Encapsulated PostScript Interchange format
EPT EPT rw- Encapsulated PostScript with TIFF preview
EPT2 EPT rw- Encapsulated PostScript Level II with TIFF preview
EPT3 EPT rw+ Encapsulated PostScript Level III with TIFF preview
ERF DNG r-- Epson RAW Format (0.21.0-Beta1)
EXR EXR rw- High Dynamic-range (HDR) (OpenEXR 3.1.3)
FARBFELD* FARBFELD rw- Farbfeld
FAX* FAX rw+ Group 3 FAX
FAX machines use non-square pixels which are 1.5 times wider than
they are tall but computer displays use square pixels, therefore
FAX images may appear to be narrow unless they are explicitly
resized using a geometry of "150x100%".
FF* FARBFELD rw- Farbfeld
FILE* URL r-- Uniform Resource Locator (file://)
FITS* FITS rw+ Flexible Image Transport System
FL32* FL32 rw- FilmLight
FLIF* FLIF rw+ Free Lossless Image Format (libflif 0.0.2 [0000])
FLV VIDEO rw+ Flash Video Stream
FPX FPX --- FlashPix Format
FRACTAL* PLASMA r-- Plasma fractal image
FTP* URL r-- Uniform Resource Locator (ftp://)
FTS* FITS rw+ Flexible Image Transport System
FTXT* FTXT rw- Formatted text image
G3* FAX rw- Group 3 FAX
G4* FAX rw- Group 4 FAX
GIF* GIF rw+ CompuServe graphics interchange format
GIF87* GIF rw- CompuServe graphics interchange format (version 87a)
GRADIENT* GRADIENT r-- Gradual linear passing from one shade to another
GRAY* GRAY rw+ Raw gray samples
GRAYA* GRAY rw+ Raw gray and alpha samples
GROUP4* TIFF rw- Raw CCITT Group4
GV DOT --- Graphviz
HALD* HALD r-- Identity Hald color lookup table image
HDR* HDR rw+ Radiance RGBE image format
HEIC HEIC r-- High Efficiency Image Format (1.14.0)
HEIF HEIC r-- High Efficiency Image Format (1.14.0)
HISTOGRAM* HISTOGRAM -w- Histogram of the image
HRZ* HRZ rw- Slow Scan TeleVision
HTM* HTML -w- Hypertext Markup Language and a client-side image map
HTML* HTML -w- Hypertext Markup Language and a client-side image map
HTTP* URL r-- Uniform Resource Locator (http://)
HTTPS* URL r-- Uniform Resource Locator (https://)
ICB* TGA rw- Truevision Targa image
ICO* ICON rw+ Microsoft icon
ICON* ICON rw- Microsoft icon
IIQ DNG r-- Phase One Raw Image Format (0.21.0-Beta1)
INFO INFO -w+ The image format and characteristics
INLINE* INLINE rw+ Base64-encoded inline images
IPL* IPL rw+ IPL Image Sequence
ISOBRL* BRAILLE -w- ISO/TR 11548-1 format
ISOBRL6* BRAILLE -w- ISO/TR 11548-1 format 6dot
J2C* JP2 rw- JPEG-2000 Code Stream Syntax (2.5.0)
J2K* JP2 rw- JPEG-2000 Code Stream Syntax (2.5.0)
JBG* JBIG --- Joint Bi-level Image experts Group interchange format
JBIG* JBIG --- Joint Bi-level Image experts Group interchange format
JNG* PNG rw- JPEG Network Graphics
See http://www.libpng.org/pub/mng/ for details about the JNG
format.
JNX* JNX r-- Garmin tile format
JP2* JP2 rw- JPEG-2000 File Format Syntax (2.5.0)
JPC* JP2 rw- JPEG-2000 Code Stream Syntax (2.5.0)
JPE* JPEG rw- Joint Photographic Experts Group JFIF format (libjpeg-turbo 2.1.1)
JPEG* JPEG rw- Joint Photographic Experts Group JFIF format (libjpeg-turbo 2.1.1)
JPG* JPEG rw- Joint Photographic Experts Group JFIF format (libjpeg-turbo 2.1.1)
JPM* JP2 rw- JPEG-2000 File Format Syntax (2.5.0)
JPS* JPEG rw- Joint Photographic Experts Group JFIF format (libjpeg-turbo 2.1.1)
JPT* JP2 rw- JPEG-2000 File Format Syntax (2.5.0)
JSON JSON -w+ The image format and characteristics
JXL* JXL rw+ JPEG XL (ISO/IEC 18181) (libjxl 0.7.0)
K25 DNG r-- Kodak Digital Camera Raw Image Format (0.21.0-Beta1)
KDC DNG r-- Kodak Digital Camera Raw Image Format (0.21.0-Beta1)
KERNEL* KERNEL -w- Morphology Kernel
LABEL* LABEL r-- Image label
M2V VIDEO rw+ MPEG Video Stream
M4V VIDEO rw+ Raw VIDEO-4 Video
MAC* MAC r-- MAC Paint
MAP* MAP rw- Colormap intensities and indices
MASK* MASK rw+ Image Clip Mask
MAT MAT rw+ MATLAB level 5 image format
MATTE* MATTE -w+ MATTE format
MEF DNG r-- Mamiya Raw Image File (0.21.0-Beta1)
MIFF* MIFF rw+ Magick Image File Format
MKV VIDEO rw+ Multimedia Container
MNG* PNG rw+ Multiple-image Network Graphics (libpng 1.6.38)
See http://www.libpng.org/pub/mng/ for details about the MNG
format.
MONO* MONO rw- Raw bi-level bitmap
MOV VIDEO rw+ MPEG Video Stream
MP4 VIDEO rw+ VIDEO-4 Video Stream
MPC* MPC rw+ Magick Pixel Cache image format
MPEG VIDEO rw+ MPEG Video Stream
MPG VIDEO rw+ MPEG Video Stream
MRW DNG r-- Sony (Minolta) Raw Image File (0.21.0-Beta1)
MSL* MSL rw+ Magick Scripting Language
MSVG* SVG rw+ ImageMagick's own SVG internal renderer
MTV* MTV rw+ MTV Raytracing image format
MVG* MVG rw- Magick Vector Graphics
NEF DNG r-- Nikon Digital SLR Camera Raw Image File (0.21.0-Beta1)
NRW DNG r-- Nikon Digital SLR Camera Raw Image File (0.21.0-Beta1)
NULL* NULL rw- Constant image of uniform color
ORA ORA r-- OpenRaster format
ORF DNG r-- Olympus Digital Camera Raw Image File (0.21.0-Beta1)
OTB* OTB rw- On-the-air bitmap
OTF* TTF r-- Open Type font (Freetype 2.12.1)
PAL* UYVY rw- 16bit/pixel interleaved YUV
PALM* PALM rw+ Palm pixmap
PAM* PNM rw+ Common 2-dimensional bitmap format
PANGO* PANGO r-- Pango Markup Language (Pangocairo 1.45.2)
PATTERN* PATTERN r-- Predefined pattern
PBM* PNM rw+ Portable bitmap format (black and white)
PCD* PCD rw- Photo CD
PCDS* PCD rw- Photo CD
PCL PCL rw+ Printer Control Language
PCT* PICT rw- Apple Macintosh QuickDraw/PICT
PCX* PCX rw- ZSoft IBM PC Paintbrush
PDB* PDB rw+ Palm Database ImageViewer Format
PDF PDF rw+ Portable Document Format
PDFA PDF rw+ Portable Document Archive Format
PEF DNG r-- Pentax Electronic File (0.21.0-Beta1)
PES* PES r-- Embrid Embroidery Format
PFA* TTF r-- Postscript Type 1 font (ASCII) (Freetype 2.12.1)
PFB* TTF r-- Postscript Type 1 font (binary) (Freetype 2.12.1)
PFM* PNM rw+ Portable float format
PGM* PNM rw+ Portable graymap format (gray scale)
PGX* PGX rw- JPEG 2000 uncompressed format
PHM* PNM rw+ Portable half float format
PICON* XPM rw- Personal Icon
PICT* PICT rw- Apple Macintosh QuickDraw/PICT
PIX* PIX r-- Alias/Wavefront RLE image format
PJPEG* JPEG rw- Joint Photographic Experts Group JFIF format (libjpeg-turbo 2.1.1)
PLASMA* PLASMA r-- Plasma fractal image
PNG* PNG rw- Portable Network Graphics (libpng 1.6.38)
See http://www.libpng.org/ for details about the PNG format.
PNG00* PNG rw- PNG inheriting bit-depth, color-type from original, if possible
PNG24* PNG rw- opaque or binary transparent 24-bit RGB (zlib 1.2.12)
PNG32* PNG rw- opaque or transparent 32-bit RGBA
PNG48* PNG rw- opaque or binary transparent 48-bit RGB
PNG64* PNG rw- opaque or transparent 64-bit RGBA
PNG8* PNG rw- 8-bit indexed with optional binary transparency
PNM* PNM rw+ Portable anymap
POCKETMOD PDF rw+ Pocketmod Personal Organizer
PPM* PNM rw+ Portable pixmap format (color)
PS PS rw+ PostScript
PS2 PS2 -w+ Level II PostScript
PS3 PS3 -w+ Level III PostScript
PSB* PSD rw+ Adobe Large Document Format
PSD* PSD rw+ Adobe Photoshop bitmap
PTIF* TIFF rw+ Pyramid encoded TIFF
PWP* PWP r-- Seattle Film Works
QOI* QOI rw- Quite OK image format
RADIAL-GRADIENT* GRADIENT r-- Gradual radial passing from one shade to another
RAF DNG r-- Fuji CCD-RAW Graphic File (0.21.0-Beta1)
RAS* SUN rw+ SUN Rasterfile
RAW DNG r-- Raw (0.21.0-Beta1)
RGB* RGB rw+ Raw red, green, and blue samples
RGB565* RGB r-- Raw red, green, blue samples in 565 format
RGBA* RGB rw+ Raw red, green, blue, and alpha samples
RGBO* RGB rw+ Raw red, green, blue, and opacity samples
RGF* RGF rw- LEGO Mindstorms EV3 Robot Graphic Format (black and white)
RLA* RLA r-- Alias/Wavefront image
RLE* RLE r-- Utah Run length encoded image
RMF DNG r-- Raw Media Format (0.21.0-Beta1)
RSVG* SVG rw+ Librsvg SVG renderer (RSVG 2.40.20)
RW2 DNG r-- Panasonic Lumix Raw Image (0.21.0-Beta1)
SCR* SCR r-- ZX-Spectrum SCREEN$
SCREENSHOT* SCREENSHO r-- Screen shot
SCT* SCT r-- Scitex HandShake
SFW* SFW r-- Seattle Film Works
SGI* SGI rw+ Irix RGB image
SHTML* HTML -w- Hypertext Markup Language and a client-side image map
SIX* SIXEL rw- DEC SIXEL Graphics Format
SIXEL* SIXEL rw- DEC SIXEL Graphics Format
SPARSE-COLOR* TXT -w+ Sparse Color
SR2 DNG r-- Sony Raw Format 2 (0.21.0-Beta1)
SRF DNG r-- Sony Raw Format (0.21.0-Beta1)
STEGANO* STEGANO r-- Steganographic image
STRIMG* STRIMG rw- String to image and back
SUN* SUN rw+ SUN Rasterfile
SVG* SVG rw+ Scalable Vector Graphics (RSVG 2.40.20)
SVGZ* SVG rw+ Compressed Scalable Vector Graphics (RSVG 2.40.20)
TEXT* TXT r-- Text
TGA* TGA rw- Truevision Targa image
THUMBNAIL* THUMBNAIL -w+ EXIF Profile Thumbnail
TIFF* TIFF rw+ Tagged Image File Format (LIBTIFF, Version 4.3.0)
TIFF64* TIFF rw+ Tagged Image File Format (64-bit) (LIBTIFF, Version 4.3.0)
TILE* TILE r-- Tile image with a texture
TIM* TIM r-- PSX TIM
TM2* TIM2 r-- PS2 TIM2
TTC* TTF r-- TrueType font collection (Freetype 2.12.1)
TTF* TTF r-- TrueType font (Freetype 2.12.1)
TXT* TXT rw+ Text
UBRL* BRAILLE -w- Unicode Text format
UBRL6* BRAILLE -w- Unicode Text format 6dot
UIL* UIL -w- X-Motif UIL table
UYVY* UYVY rw- 16bit/pixel interleaved YUV
VDA* TGA rw- Truevision Targa image
VICAR* VICAR rw- Video Image Communication And Retrieval
VID* VID rw+ Visual Image Directory
VIFF* VIFF rw+ Khoros Visualization image
VIPS* VIPS rw+ VIPS image
VST* TGA rw- Truevision Targa image
WBMP* WBMP rw- Wireless Bitmap (level 0) image
WEBM VIDEO rw+ Open Web Media
WEBP* WEBP rw+ WebP Image Format (libwebp 1.2.2 [020F])
WMF EMF r-- Windows Meta File
WMV VIDEO rw+ Windows Media Video
WPG* WPG r-- Word Perfect Graphics
X3F DNG r-- Sigma Camera RAW Picture File (0.21.0-Beta1)
XBM* XBM rw- X Windows system bitmap (black and white)
XC* XC r-- Constant image uniform color
XCF* XCF r-- GIMP image
XPM* XPM rw- X Windows system pixmap (color)
XPS XPS r-- Microsoft XML Paper Specification
XV* VIFF rw+ Khoros Visualization image
YAML YAML -w+ The image format and characteristics
YCbCr* YCbCr rw+ Raw Y, Cb, and Cr samples
YCbCrA* YCbCr rw+ Raw Y, Cb, Cr, and alpha samples
YUV* YUV rw- CCIR 601 4:1:1 or 4:2:2
* native blob support
r read support
w write support
+ support for multiple images
透過 CLI 命令轉換圖檔
在使用 ImageMagick 命令列工具時，在 Linux 與 macOS 作業系統下，其主程式預設為 convert，但是在 Windows 作業系統下已經有內建一個 C:\Windows\System32\convert.exe 執行檔，所以在 Windows 安裝好 ImageMagick 之後的主程式為 magick.exe！
我們先來嘗試轉換單張圖片：
-
預設轉換設定
將 demo.png 轉換為 demo1.avif 格式，使用預設品質設定
magick demo.png demo1.avif
圖片大小從 602 KB (617,214 bytes) 降為 107 KB (110,241 bytes)！
-
轉換設定 80% 影像品質
將 demo.png 轉換為 demo2.avif 格式，使用 80% 品質進行轉換，這種轉換會產生一個「有損壓縮」的圖片
magick -quality "80" demo.png demo2.avif
圖片大小從 602 KB (617,214 bytes) 降為 178 KB (182,523 bytes)！
-
使用進階的選項設定，提供更好的壓縮效果，但轉換時間會拉長很多
將 demo.png 轉換為 demo3.avif 格式，並使用 heic 外掛(delegate)提供的 speed 參數，這裡的 heic:speed=2 是指轉換速度，其值從 1 (最慢/品質與壓縮比最高) ~ 10 (最快/品質與壓縮比最差)。
magick -define "heic:speed=2" demo.png demo3.avif
圖片大小從 602 KB (617,214 bytes) 降為 82.7 KB (84,759 bytes)！
透過 PowerShell 批次轉換圖檔
當你決定好轉換的參數，就可以透過 PowerShell 批次轉換圖檔了！
-
將當前目錄下所有 *.png 圖檔轉換為 *.avif 與 *.webp 格式
$sourceFolder = "${PWD.Path}\*"
$filePatterns = '*.png','*.jpg','*.gif'
Get-ChildItem -Path $sourceFolder -Include $filePatterns -File | ForEach-Object {
$name = $_.FullName
$webp = [System.IO.Path]::ChangeExtension($name,".webp")
$avif = [System.IO.Path]::ChangeExtension($name,".avif")
echo "Orig: $name"
echo "WebP: $webp"
magick -quality 75 "$name" "$webp"
echo "AVIF: $avif"
magick -quality 75 "$name" "$avif"
echo ""
}
-
將當前目錄包含其子目錄下所有 *.png 圖檔轉換為 *.avif 與 *.webp 格式
$sourceFolder = "${PWD.Path}\*"
$filePatterns = '*.png','*.jpg','*.gif'
Get-ChildItem -Path $sourceFolder -Include $filePatterns -File -Recurse | ForEach-Object {
$name = $_.FullName
$webp = [System.IO.Path]::ChangeExtension($name,".webp")
$avif = [System.IO.Path]::ChangeExtension($name,".avif")
echo "Orig: $name"
echo "WebP: $webp"
magick -quality 75 "$name" "$webp"
echo "AVIF: $avif"
magick -quality 75 "$name" "$avif"
echo ""
}
透過 Bash 與 Docker 批次轉換圖檔
當你決定好轉換的參數，也可以透過 Docker 批次轉換圖檔！
-
將當前目錄下所有 *.png 圖檔轉換為 *.avif 與 *.webp 格式
for file in $(find $PWD -maxdepth 1 -name "*.png" -o -name "*.jpg" -o -name "*.gif"); do
echo $file
file=${file/$PWD/\/imgs}
docker run --rm -w '/imgs' -v "$PWD:/imgs" "dpokidov/imagemagick" ${file} ${file/.png/.avif}
docker run --rm -w '/imgs' -v "$PWD:/imgs" "dpokidov/imagemagick" ${file} ${file/.png/.webp}
done
-
將當前目錄包含其子目錄下所有 *.png 圖檔轉換為 *.avif 與 *.webp 格式
for file in $(find $PWD -name "*.png" -o -name "*.jpg" -o -name "*.gif"); do
echo $file
file=${file/$PWD/\/imgs}
docker run --rm -w '/imgs' -v "$PWD:/imgs" "dpokidov/imagemagick" ${file} ${file/.png/.avif}
docker run --rm -w '/imgs' -v "$PWD:/imgs" "dpokidov/imagemagick" ${file} ${file/.png/.webp}
done
相關連結