NAME¶

tjbench - benchmark the performance of libjpeg-turbo

DESCRIPTION¶

tjbench is a JPEG decompression/compression benchmark part of libjpeg-turbo.

USAGE¶

tjbench <Inputfile (BMP|PPM)> <Quality> [options]

tjbench <Inputfile (JPG)> [options]

OPTIONS¶

-alloc = Dynamically allocate JPEG image buffers -bmp = Generate output images in Windows Bitmap format (default = PPM) -bottomup = Test bottom-up compression/decompression -tile = Test performance of the codec when the image is encoded as separate

tiles of varying sizes.

-rgb, -bgr, -rgbx, -bgrx, -xbgr, -xrgb =

Test the specified color conversion path in the codec (default = BGR)

-cmyk = Indirectly test YCCK JPEG compression/decompression (the source

and destination bitmaps are still RGB.

The conversion is done

internally prior to compression or after decompression.)

-fastupsample = Use the fastest chrominance upsampling algorithm available in

the underlying codec

-fastdct = Use the fastest DCT/IDCT algorithms available in the underlying

codec

-accuratedct = Use the most accurate DCT/IDCT algorithms available in the

underlying codec

-progressive = Use progressive entropy coding in JPEG images generated by

compression and transform operations.

-subsamp <s> = When testing JPEG compression, this option specifies the level

of chrominance subsampling to use (<s> = 444, 422, 440, 420, 411, or GRAY). The default is to test Grayscale, 4:2:0, 4:2:2, and 4:4:4 in sequence.

-quiet = Output results in tabular rather than verbose format -yuv = Test YUV encoding/decoding functions -yuvpad <p> = If testing YUV encoding/decoding, this specifies the number of

bytes to which each row of each plane in the intermediate YUV image is padded (default = 1)

-scale M/N = Scale down the width/height of the decompressed JPEG image by a

factor of M/N (M/N = 2/1, 15/8, 7/4, 13/8, 3/2, 11/8, 5/4, 9/8, 1/1, 7/8, 3/4, 5/8, 1/2, 3/8, 1/4, or 1/8)

-hflip, -vflip, -transpose, -transverse, -rot90, -rot180, -rot270 =

Perform the corresponding lossless transform prior to decompression (these options are mutually exclusive)

-grayscale = Perform lossless grayscale conversion prior to decompression

test (can be combined with the other transforms above)

-copynone = Do not copy any extra markers (including EXIF and ICC profile data)

when transforming the image.

-benchtime <t> = Run each benchmark for at least <t> seconds (default = 5.0) -warmup <t> = Run each benchmark for <t> seconds (default = 1.0) prior to

starting the timer, in order to prime the caches and thus improve the consistency of the results.

-componly = Stop after running compression tests. Do not test decompression. -nowrite = Do not write reference or output images (improves consistency of

performance measurements.)

-limitscans = Refuse to decompress or transform progressive JPEG images that

have an unreasonably large number of scans

-stoponwarning = Immediately discontinue the current

compression/decompression/transform operation if the underlying codec throws a warning (non-fatal error)

NOTE: If the quality is specified as a range (e.g. 90-100), a separate test will be performed for all quality values in the range.

COMMENT¶

This manual page was written by Mathieu Malaterre <malat@debian.org> for the Debian GNU/Linux system, but may be used by others.

COPYRIGHT¶

Copyright (C)2009-2019, 2021 D. R. Commander. All Rights Reserved.