img2webp.1 (4728B)
1 .\" Hey, EMACS: -*- nroff -*- 2 .TH IMG2WEBP 1 "November 26, 2024" 3 .SH NAME 4 img2webp \- create animated WebP file from a sequence of input images. 5 .SH SYNOPSIS 6 .B img2webp 7 [file_options] [[frame_options] frame_file]... [\-o webp_file] 8 .br 9 .B img2webp argument_file_name 10 .br 11 .SH DESCRIPTION 12 This manual page documents the 13 .B img2webp 14 command. 15 .PP 16 \fBimg2webp\fP compresses a sequence of images using the animated WebP format. 17 Input images can either be PNG, JPEG, TIFF or WebP. 18 If a single file name (not starting with the character '\-') is supplied as 19 the argument, the command line arguments are actually tokenized from this file. 20 This allows for easy scripting or using a large number of arguments. 21 .SH FILE-LEVEL OPTIONS 22 The file-level options are applied at the beginning of the compression process, 23 before the input frames are read. 24 .TP 25 .BI \-o " string 26 Specify the name of the output WebP file. 27 .TP 28 .BI \-min_size 29 Encode images to achieve smallest size. This disables key frame insertion and 30 picks the parameters resulting in the smallest output for each frame. It uses 31 lossless compression by default, but can be combined with \-q, \-m, \-lossy or 32 \-mixed options. 33 .TP 34 .BI \-kmin " int 35 .TP 36 .BI \-kmax " int 37 Specify the minimum and maximum distance between consecutive key frames 38 (independently decodable frames) in the output animation. The tool will insert 39 some key frames into the output animation as needed so that this criteria is 40 satisfied. 41 .br 42 .B \-mixed 43 Mixed compression mode: optimize compression of the image by picking either 44 lossy or lossless compression for each frame heuristically. This global 45 option disables the local option \fB-lossy\fP and \fB-lossless\fP . 46 .TP 47 .BI \-near_lossless " int 48 Specify the level of near\-lossless image preprocessing. This option adjusts 49 pixel values to help compressibility, but has minimal impact on the visual 50 quality. It triggers lossless compression mode automatically. The range is 0 51 (maximum preprocessing) to 100 (no preprocessing, the default). The typical 52 value is around 60. Note that lossy with \fB\-q 100\fP can at times yield 53 better results. 54 .TP 55 .B \-sharp_yuv 56 Use more accurate and sharper RGB->YUV conversion. Note that this process is 57 slower than the default 'fast' RGB->YUV conversion. 58 .TP 59 .BI \-loop " int 60 Specifies the number of times the animation should loop. Using '0' 61 means 'loop indefinitely'. 62 .TP 63 .BI \-v 64 Be more verbose. 65 .TP 66 .B \-h, \-help 67 A short usage summary. 68 .TP 69 .B \-version 70 Print the version numbers of the relevant libraries used. 71 72 .SH PER-FRAME OPTIONS 73 The per-frame options are applied for the images following as arguments in the 74 command line. They can be modified any number of times preceding each particular 75 input image. 76 .TP 77 .BI \-d " int 78 Specify the image duration in milliseconds. 79 .TP 80 .B \-lossless, \-lossy 81 Compress the next image(s) using lossless or lossy compression mode. The 82 default mode is lossless. 83 .TP 84 .BI \-q " float 85 Specify the compression factor between 0 and 100. The default is 75. 86 .TP 87 .BI \-m " int 88 Specify the compression method to use. This parameter controls the 89 trade off between encoding speed and the compressed file size and quality. 90 Possible values range from 0 to 6. Default value is 4. 91 When higher values are used, the encoder will spend more time inspecting 92 additional encoding possibilities and decide on the quality gain. 93 Lower value can result in faster processing time at the expense of 94 larger file size and lower compression quality. 95 .TP 96 .B \-exact, \-noexact 97 Preserve or alter RGB values in transparent area. The default is 98 \fB-noexact\fP, to help compressibility. Note \fB\-noexact\fP may cause 99 artifacts in frames compressed with \fB\-lossy\fP. 100 101 .SH EXIT STATUS 102 If there were no problems during execution, \fBimg2webp\fP exits with the value 103 of the C constant \fBEXIT_SUCCESS\fP. This is usually zero. 104 .PP 105 If an error occurs, \fBimg2webp\fP exits with the value of the C constant 106 \fBEXIT_FAILURE\fP. This is usually one. 107 108 .SH EXAMPLE 109 img2webp -loop 2 in0.png -lossy in1.jpg -d 80 in2.tiff -o out.webp 110 .br 111 112 .SH AUTHORS 113 \fBimg2webp\fP is a part of libwebp and was written by the WebP team. 114 .br 115 The latest source tree is available at 116 https://chromium.googlesource.com/webm/libwebp 117 .PP 118 This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>, 119 for the Debian project (and may be used by others). 120 121 .SH REPORTING BUGS 122 Please report all bugs to the issue tracker: 123 https://issues.webmproject.org 124 .br 125 Patches welcome! See this page to get started: 126 https://www.webmproject.org/code/contribute/submitting\-patches/ 127 128 .SH SEE ALSO 129 .BR webpmux (1), 130 .BR gif2webp (1) 131 .br 132 Please refer to https://developers.google.com/speed/webp/ for additional 133 information.