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Last active November 20, 2015 06:28
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#!/bin/sh
set -x
convert -size 1000x1000 canvas:white date1.png
sleep 2
convert -size 1000x1000 canvas:white date2.png
sleep 2
convert -size 1000x1000 canvas:white date1.jpg
sleep 2
convert -size 1000x1000 canvas:white date2.jpg
#f="+set date:create +set date:modify"
#f="-define png:exclude-chunks=time"
#f="-define png:exclude-chunks=tIME"
#f="-define png:exclude-chunks=date,time"
f="-define png:exclude-chunks=date -define png:exclude-chunks=time"
sleep 2
convert $f -size 1000x1000 canvas:white nodate1.png
sleep 2
convert $f -size 1000x1000 canvas:white nodate2.png
identify -verbose date1.png > date1.png.i
identify -verbose date2.png > date2.png.i
identify -verbose date1.png > date1.jpg.i
identify -verbose date2.png > date2.jpg.i
identify -verbose nodate1.png > nodate1.png.i
identify -verbose nodate2.png > nodate2.png.i
openssl md5 date[12].png
openssl md5 date[12].jpg
openssl md5 nodate[12].png
diff -u date1.png.i date2.png.i
diff -u date1.jpg.i date2.jpg.i
diff -u nodate1.png.i nodate2.png.i
@wkoszek
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wkoszek commented Nov 20, 2015

+ convert -size 1000x1000 canvas:white date1.png
+ sleep 2
+ convert -size 1000x1000 canvas:white date2.png
+ sleep 2
+ convert -size 1000x1000 canvas:white date1.jpg
+ sleep 2
+ convert -size 1000x1000 canvas:white date2.jpg
+ f='-define png:exclude-chunks=date -define png:exclude-chunks=time'
+ sleep 2
+ convert -define png:exclude-chunks=date -define png:exclude-chunks=time -size 1000x1000 canvas:white nodate1.png
+ sleep 2
+ convert -define png:exclude-chunks=date -define png:exclude-chunks=time -size 1000x1000 canvas:white nodate2.png
+ identify -verbose date1.png
+ identify -verbose date2.png
+ identify -verbose date1.png
+ identify -verbose date2.png
+ identify -verbose nodate1.png
+ identify -verbose nodate2.png
+ openssl md5 date1.png date2.png
MD5(date1.png)= 55e1e424607f545e726ba6c18cca0562
MD5(date2.png)= 44f73438b4bb21a605c43a15e1d68482
+ openssl md5 date1.jpg date2.jpg
MD5(date1.jpg)= 62e7516fac87981fb929b47384ed4584
MD5(date2.jpg)= 62e7516fac87981fb929b47384ed4584
+ openssl md5 nodate1.png nodate2.png
MD5(nodate1.png)= b2afa157a3373091b2f4214ce4910ba2
MD5(nodate2.png)= b3175e504675801223a68624c5be1d4f
+ diff -u date1.png.i date2.png.i
--- date1.png.i 2015-11-19 22:34:35.000000000 -0800
+++ date2.png.i 2015-11-19 22:34:36.000000000 -0800
@@ -1,4 +1,4 @@
-Image: date1.png
+Image: date2.png
   Format: PNG (Portable Network Graphics)
   Mime type: image/png
   Class: PseudoClass
@@ -48,8 +48,8 @@
   Compression: Zip
   Orientation: Undefined
   Properties:
-    date:create: 2015-11-19T22:34:25-08:00
-    date:modify: 2015-11-19T22:34:25-08:00
+    date:create: 2015-11-19T22:34:27-08:00
+    date:modify: 2015-11-19T22:34:27-08:00
     png:bKGD: chunk was found (see Background color, above)
     png:cHRM: chunk was found (see Chromaticity, above)
     png:gAMA: gamma=0.45455 (See Gamma, above)
@@ -60,10 +60,10 @@
     png:IHDR.interlace_method: 0 (Not interlaced)
     png:IHDR.width,height: 1000, 1000
     png:text: 2 tEXt/zTXt/iTXt chunks were found
-    png:tIME: 2015-11-19T22:34:25Z
+    png:tIME: 2015-11-19T22:34:27Z
     signature: fe1798ad57945703208c626a0551c474bc6c4a385b6da5ae2a3e2c317b4cc06c
   Artifacts:
-    filename: date1.png
+    filename: date2.png
     verbose: true
   Tainted: False
   Filesize: 701B
+ diff -u date1.jpg.i date2.jpg.i
--- date1.jpg.i 2015-11-19 22:34:36.000000000 -0800
+++ date2.jpg.i 2015-11-19 22:34:36.000000000 -0800
@@ -1,4 +1,4 @@
-Image: date1.png
+Image: date2.png
   Format: PNG (Portable Network Graphics)
   Mime type: image/png
   Class: PseudoClass
@@ -48,8 +48,8 @@
   Compression: Zip
   Orientation: Undefined
   Properties:
-    date:create: 2015-11-19T22:34:25-08:00
-    date:modify: 2015-11-19T22:34:25-08:00
+    date:create: 2015-11-19T22:34:27-08:00
+    date:modify: 2015-11-19T22:34:27-08:00
     png:bKGD: chunk was found (see Background color, above)
     png:cHRM: chunk was found (see Chromaticity, above)
     png:gAMA: gamma=0.45455 (See Gamma, above)
@@ -60,15 +60,15 @@
     png:IHDR.interlace_method: 0 (Not interlaced)
     png:IHDR.width,height: 1000, 1000
     png:text: 2 tEXt/zTXt/iTXt chunks were found
-    png:tIME: 2015-11-19T22:34:25Z
+    png:tIME: 2015-11-19T22:34:27Z
     signature: fe1798ad57945703208c626a0551c474bc6c4a385b6da5ae2a3e2c317b4cc06c
   Artifacts:
-    filename: date1.png
+    filename: date2.png
     verbose: true
   Tainted: False
   Filesize: 701B
   Number pixels: 1M
-  Pixels per second: 333.33GB
+  Pixels per second: 500GB
   User time: 0.000u
   Elapsed time: 0:01.000
   Version: ImageMagick 6.9.1-1 Q16 x86_64 2015-04-15 http://www.imagemagick.org
+ diff -u nodate1.png.i nodate2.png.i
--- nodate1.png.i   2015-11-19 22:34:36.000000000 -0800
+++ nodate2.png.i   2015-11-19 22:34:37.000000000 -0800
@@ -1,4 +1,4 @@
-Image: nodate1.png
+Image: nodate2.png
   Format: PNG (Portable Network Graphics)
   Mime type: image/png
   Class: PseudoClass
@@ -48,8 +48,8 @@
   Compression: Zip
   Orientation: Undefined
   Properties:
-    date:create: 2015-11-19T22:34:33-08:00
-    date:modify: 2015-11-19T22:34:33-08:00
+    date:create: 2015-11-19T22:34:35-08:00
+    date:modify: 2015-11-19T22:34:35-08:00
     png:bKGD: chunk was found (see Background color, above)
     png:cHRM: chunk was found (see Chromaticity, above)
     png:gAMA: gamma=0.45455 (See Gamma, above)
@@ -62,7 +62,7 @@
     png:text: 2 tEXt/zTXt/iTXt chunks were found
     signature: fe1798ad57945703208c626a0551c474bc6c4a385b6da5ae2a3e2c317b4cc06c
   Artifacts:
-    filename: nodate1.png
+    filename: nodate2.png
     verbose: true
   Tainted: False
   Filesize: 682B

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