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file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-22T02:46:14-07:00
by Petr
Code: Select all
x86_64$ convert test.jpg test1.x86_64.jpg
x86_64$ ls -l test1.x86_64.jpg
-rw-r--r-- 1 linux users 715665 Jan 22 10:27 test1.x86_64.jpg
x86_64$
Code: Select all
s390x$ convert test.jpg test1.s390x.jpg
s390x$ ls -l test1.s390x.jpg
-rw-r--r-- 1 linux users 715527 Jan 22 04:24 test1.s390x.jpg
s390x$
For test.jpg can stand e. g. git/cups/doc/images/smiley.jpg, and my original testcase was real photo I can provide. Resulting images viewed on x86_64 via display do NOT look different at the first human-eye sight.
Is that expected? Can be and can be proved in some way that resulting images are equal despite different file sizes? I did
Code: Select all
s390x$ convert test1.s390x.jpg test1.s390x.png
and
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x86_64$ convert test1.s390x.jpg test1.s390x.png
but, according to hexdump, test1.s390x.png and test1.x86_64.png differ in IDAT chunk (and in file sizes too).
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-22T02:54:43-07:00
by Petr
According to jpegdump, resulting images differ in Huffman tables.
Code: Select all
$ jpegdump -v -v test1.x86_64.jpg > test1.x86_64.jpg.dump
$ jpegdump -v -v test1.s390x.jpg > test1.s390x.jpg.dump
$ diff -a -upr test1.{x86_64,s390x}.jpg.dump
--- test1.x86_64.jpg.dump 2015-01-20 16:11:43.055645497 +0100
+++ test1.s390x.jpg.dump 2015-01-20 16:11:31.048497603 +0100
@@ -1,5 +1,5 @@
-test1.x86_64.jpg:
+test1.s390x.jpg:
offset $0 SOI
offset $2 APP0 (length 16)
JFIF version 0101, 300 x 300 dpi
@@ -365,13 +365,13 @@ offset $5b75 SOF0 (baseline DCT Huffman)
offset $5b88 DHT (length 30)
table 0
bits 1 (codes= 0)
- bits 2 (codes= 1) $05
- bits 3 (codes= 5) $00 $02 $03 $04 $06
- bits 4 (codes= 1) $01
- bits 5 (codes= 1) $07
- bits 6 (codes= 1) $08
- bits 7 (codes= 1) $09
- bits 8 (codes= 1) $0a
+ bits 2 (codes= 0)
+ bits 3 (codes= 7) $00 $01 $02 $03 $04 $05 $06
+ bits 4 (codes= 1) $07
+ bits 5 (codes= 1) $08
+ bits 6 (codes= 1) $09
+ bits 7 (codes= 1) $0a
+ bits 8 (codes= 0)
bits 9 (codes= 0)
bits 10 (codes= 0)
bits 11 (codes= 0)
@@ -393,17 +393,17 @@ offset $5ba8 DHT (length 87)
bits 9 (codes= 5) $08 $15 $23 $52 $71
bits 10 (codes= 4) $33 $62 $81 $91
bits 11 (codes= 8) $16 $24 $72 $82 $a1 $b1 $c1 $f0
- bits 12 (codes= 4) $09 $43 $92 $d1
- bits 13 (codes= 4) $a2 $b2 $e1 $f1
- bits 14 (codes= 2) $17 $25
+ bits 12 (codes= 3) $43 $92 $d1
+ bits 13 (codes= 7) $09 $17 $25 $a2 $b2 $e1 $f1
+ bits 14 (codes= 0)
bits 15 (codes= 2) $34 $53
- bits 16 (codes= 19) $c2 $d2 $e2 $f2 $18 $26 $44 $63 $0a $35 $73 $27 $54 $83 $45 $55 $65 $84 $93
+ bits 16 (codes= 19) $c2 $d2 $e2 $f2 $18 $26 $44 $63 $0a $35 $73 $27 $45 $83 $54 $55 $65 $84 $93
offset $5c01 DHT (length 28)
table 1
bits 1 (codes= 0)
bits 2 (codes= 3) $00 $02 $03
- bits 3 (codes= 1) $04
- bits 4 (codes= 1) $01
+ bits 3 (codes= 1) $01
+ bits 4 (codes= 1) $04
bits 5 (codes= 1) $05
bits 6 (codes= 1) $06
bits 7 (codes= 1) $07
@@ -427,17 +427,17 @@ offset $5c1f DHT (length 69)
bits 7 (codes= 3) $05 $41 $42
bits 8 (codes= 5) $14 $51 $52 $61 $71
bits 9 (codes= 6) $23 $81 $91 $a1 $b1 $f0
- bits 10 (codes= 5) $06 $62 $c1 $d1 $e1
- bits 11 (codes= 4) $15 $33 $72 $f1
- bits 12 (codes= 2) $24 $82
- bits 13 (codes= 1) $43
- bits 14 (codes= 3) $16 $34 $92
- bits 15 (codes= 2) $07 $53
- bits 16 (codes= 7) $a2 $c2 $b2 $d2 $25 $35 $73
+ bits 10 (codes= 6) $06 $33 $62 $c1 $d1 $e1
+ bits 11 (codes= 3) $15 $72 $f1
+ bits 12 (codes= 0)
+ bits 13 (codes= 2) $24 $82
+ bits 14 (codes= 0)
+ bits 15 (codes= 2) $43 $16
+ bits 16 (codes= 11) $92 $07 $34 $35 $53 $a2 $c2 $25 $b2 $d2 $73
offset $5c66 SOS (length 12)
components 3
id 1 dc table 0, ac table 0
id 2 dc table 1, ac table 1
id 3 dc table 1, ac table 1
spectral selection 0 to 63, bit position high 0, low 0
-offset $aeb8f EOI
+offset $aeb05 EOI
When -define jpeg:optimize-coding=false parameter to convert is used, then Huffman tables do not differ.
Code: Select all
--- test1.x86_64.jpg.dump 2015-01-20 16:26:52.177027461 +0100
+++ test1.s390x.jpg.dump 2015-01-20 16:26:53.842053605 +0100
@@ -1,5 +1,5 @@
-test1.x86_64.jpg:
+test1.s390x.jpg:
offset $0 SOI
offset $2 APP0 (length 16)
JFIF version 0101, 300 x 300 dpi
@@ -440,4 +440,4 @@ offset $5d38 SOS (length 12)
id 2 dc table 1, ac table 1
id 3 dc table 1, ac table 1
spectral selection 0 to 63, bit position high 0, low 0
-offset $b4b31 EOI
+offset $b48e0 EOI
Nevertheless even then file size of resulting image differs as can be also seen from EOI offsets difference, if I understand correctly.
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-22T06:32:14-07:00
by Petr
Original test was performed with
ImageMagick 6.8.8-1
libjpeg-turbo 1.3.1
I tested also with
ImageMagick 6.8.8-1
jpeg 9a
With this setup, I get smiley.jpg converted to the same image (checked with md5sum). That is not true for my original (real photo) testcase:
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-rw-r--r-- 1 linux users 715719 Jan 22 08:19 test1.s390x.IJG.jpg
-rw-r--r-- 1 linux users 715527 Jan 22 04:24 test1.s390x.jpg
-rw-r--r-- 1 linux users 715681 Jan 22 14:19 test1.x86_64.IJG.jpg
-rw-r--r-- 1 linux users 715665 Jan 22 10:27 test1.x86_64.jpg
where *IJG* was converted with jpeg 9a and others with libjpeg-turbo.
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-22T10:32:28-07:00
by snibgo
If you are converting identical input files (and the filenames are identical) on different machines but with identical versions of IM (including all libraries), I would expect the output JPEG files to be identical.
I don't understand your tests. Are you saying that, with these conditions, you get different results?
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-23T00:27:49-07:00
by Petr
Yes. The resulting files differs in file size.
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-23T10:38:39-07:00
by fmw42
Do you have the same versions of your delegate libraries (esp libjpeg) on both systems?
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-26T02:26:19-07:00
by Petr
Yes.
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-26T02:37:46-07:00
by Petr
Namely: original test with /usr/lib64/libjpeg.so.8.0.2 from libjpeg-turbo project on both s390x and x86_64. Second test (comment from 2015-01-22T14:32:14+01:00) was trough /usr/lib64/libjpeg.so.9.1.0 from IJG jpeg library and ImageMagick built against it (again, on both s390x and x86_64).
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-26T10:29:53-07:00
by fmw42
Are you forcing the quality to the same value on both systems by using -quality XX, to be sure they two systems use the same compression?
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-27T03:23:11-07:00
by Petr
Code: Select all
x86_64$ for i in 10 30 50 100; do convert test.jpg -quality $i test1.$i.jpg; ls -l test1.$i.jpg; done
-rw-r--r-- 1 linux users 75854 Jan 27 11:15 test1.10.jpg
-rw-r--r-- 1 linux users 153799 Jan 27 11:15 test1.30.jpg
-rw-r--r-- 1 linux users 215478 Jan 27 11:15 test1.50.jpg
-rw-r--r-- 1 linux users 1170498 Jan 27 11:15 test1.100.jpg
but
Code: Select all
s390x$ for i in 10 30 50 100; do convert test.jpg -quality $i test1.$i.jpg; ls -l test1.$i.jpg; done
-rw-r--r-- 1 linux users 75854 Jan 27 2015 test1.10.jpg
-rw-r--r-- 1 linux users 153799 Jan 27 2015 test1.30.jpg
-rw-r--r-- 1 linux users 215457 Jan 27 2015 test1.50.jpg
-rw-r--r-- 1 linux users 1170468 Jan 27 2015 test1.100.jpg
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-27T03:40:39-07:00
by Petr
If that would be interesting for you, I tried the differences for quality=`seq 1 100`, and I get the following. First column is quality percent and second number is file size.
Code: Select all
--- s390x.txt 2015-01-27 11:33:37.132312580 +0100
+++ x86_64.txt 2015-01-27 11:33:20.876111770 +0100
@@ -10,92 +10,92 @@
10 75854
11 80157
12 84067
-13 88451
+13 88449
14 92433
15 96950
-16 100357
+16 100366
17 104702
-18 109013
+18 109005
19 112482
20 115672
21 119904
22 124432
-23 128504
+23 128538
24 131738
25 134972
26 138449
27 142211
-28 146328
+28 146342
29 149546
30 153799
-31 157691
+31 157680
32 159895
-33 163988
-34 165988
-35 170279
-36 174223
-37 175925
-38 179534
-39 182936
-40 185192
-41 189434
-42 191592
-43 194950
-44 199716
+33 163989
+34 165982
+35 170316
+36 174221
+37 175921
+38 179546
+39 182942
+40 185207
+41 189448
+42 191616
+43 194928
+44 199685
45 201569
46 205684
47 206994
48 209626
-49 214870
-50 215457
-51 217054
-52 224394
-53 228390
-54 230940
-55 233959
+49 214837
+50 215478
+51 217036
+52 224314
+53 228366
+54 230935
+55 233948
56 237844
57 240776
-58 244407
-59 246163
+58 244383
+59 246143
60 249779
61 255611
62 258001
63 262202
-64 265171
-65 270680
-66 277145
-67 281531
-68 290082
-69 298677
-70 309321
-71 316846
-72 324213
-73 335201
-74 345570
-75 349804
-76 358629
-77 374720
-78 384279
-79 393731
-80 409572
+64 265153
+65 270647
+66 277140
+67 281517
+68 290070
+69 298675
+70 309339
+71 316849
+72 324221
+73 335227
+74 345571
+75 349778
+76 358587
+77 374719
+78 384242
+79 393690
+80 409507
81 426035
82 444737
-83 460661
-84 480883
-85 507693
-86 527867
+83 460605
+84 480852
+85 507713
+86 527862
87 543086
-88 568144
-89 588634
-90 614272
-91 635603
-92 649735
-93 682037
-94 715719
-95 751637
-96 793214
-97 834146
-98 875977
-99 980328
-100 1170468
+88 568155
+89 588668
+90 614241
+91 635553
+92 649728
+93 682035
+94 715681
+95 751641
+96 793314
+97 834139
+98 875922
+99 980391
+100 1170498
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-27T03:54:36-07:00
by Petr
But: For quality=`seq 1 100`, there's no difference in file sizes when git/cups/doc/images/smiley.jpg stands for original image (test.jpg). Today's tests was performed with IJG jpeg library as a backend. According to initial comment of this topic, there would be at least one difference (for default quality) when libjpeg-turbo would be used.
Re: file size of jpeg images created on x86_64 and s390x differ
Posted: 2015-01-27T05:33:03-07:00
by Petr
http://upload.wikimedia.org/wikipedia/c ... 5_ubt.jpeg
is one of the online image that exposes the problem for me. File size indicates the issue for -quality=69,70,71,97,99,100 (only few bytes) plus md5sum indicates the issue for -quality=37,38,68,93,94,95,96.
http://upload.wikimedia.org/wikipedia/c ... ka_NZ.jpeg
is one of the online image that does NOT expose the problem. All md5sums correspond for -quality=1..100.
