Site Building Tip |
Article Rating: Above Average
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| Author:
| 1746
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| Submitted: |
07-Oct-2005 00:38:40 |
| Imported From: |
zZine (original author: 1746)
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| If you use images on your website you probably consider width, height and resolution as the main factors involved in keeping the file size as small as possible.
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If you use images on your website you probably consider width, height and resolution as the main factors involved in keeping the file size as small as possible, but what you may not know is this: images may contain unseen information that can add substantially to file sizes. How does this happen?
This unseen information is generally called "watermarking" when referring to images, and it may be added in many ways.
- If you send your photographs or other images somewhere to be digitized and returned as a disk.
- Your camera may add a watermark although this is not common.
- The public domain or free use image may be watermarked.
- You may have no idea where your friend's image has been.
- The image editor or graphics program may add watermarks.
- If the origin of the image is unknown the watermark could be a trademark.
- An image of unknown origin could contain secret messages and these may also be encrypted.
- An unlikely but possible source of watermarks could be a site host.
Generally, watermarks are added in an attempt to protect rights to the image. My intent in this article is not meant to address legal issues, but I think that if you fully create an image with either hard or software, you should be advised if you are surrendering any rights to your images by the use of that ware,or if you own the rights. The worst case legal scenario: you discover your favorite image of your dog in commercial use, copyrighted by the company that digitized your snapshots. Some companies, like Adobe, advise you of this when processing your images.
I have seen terms of service contracts for some hosting providers that I believe could be easily interpreted to mean they are assuming the rights, although most refer to their rights to your content only for the purposes of promoting your site. That said, if you feel justified in removing existing watermarks I will give you a quick example:
The Software
- JPGCLN95 - JPG Cleaner 95 v2.1Copyright (c) 2000 Rainbow Software (http://www.rainbow-software.org/). Special thanks to PiT. This is now out in v2.6 , ZIP file contains DOS, W32Console and Win32 versions. W32Console version can only be run in Windows 95/98/ME/NT/2000 and supports long file names. DOS version runs everywhere and supports only DOS 8.3 file names. Win32 version runs in Windows 95/98/ME/NT/2000
This application is small, fast, easy to configure and can process almost as many files as you feed it. I can run through over seventy thousand in a few minutes.
For this sample I loaded a folder with 26 jpg files from CyberArmy's files repository titled "Fun". I selected these files to give me a small selection of jpgs from a variety of original sources and I have no knowledge of their history. I anticipate the owners of these images will recognize them. If you own a file, please don't think I'm patting you on the back for a clean file or criticizing you for one that contains watermarks! I made no attempt to extract or read the watermarks, for all I know you put them there to protect your rights. I altered only the copies I made, not the originals in the file on CyberArmy's server and I deleted the copies after copying the log.
The Log
- Size...name........Result
- 52k....nkf...Already clean
- 355k...lol...Already clean
- 123k...k_fagtor...Already clean
- 204k...xwyzardandenok..Already clean
- 122k...ty&amp...Already clean
- 37k....0909b8...Already clean
- 204k...0wnd! Already clean
- 1190k..argh3...Already clean
- 16k....arsch1_jpg...Already clean
- 98k....OSI_0wned2x..Already clean
- 14k....resourcefull..Already clean
- 140k...rjback...Already clean
- 114k...stripper-radio-1204..Already clean
- 44k....workbench...Already clean
- Final Size...Name................Result
- 896k...P2B'S BONG................Cleaned 5193 bytes
- 36k....Beer, All a Man needs.....Cleaned 35 bytes
- 1547...bikes_0023................Cleaned 9198 bytes
- 44k....blondes...................Cleaned 28340 bytes
- 78k....cyberarmy-net.............Cleaned 6701 bytes
- 35k....Ike Turner aka TanMonkey..Cleaned 61 bytes
- 158k...IMG_0511..................Cleaned 8623 bytes
- 73k....mod_perl..................Cleaned 54 bytes
- 845k P1010006..................Cleaned 15706 bytes
- 171k pic1......................Cleaned 16229 bytes
- 91k starchamber...............Cleaned 8216 bytes
- 73k z10.......................Cleaned 7644 bytes
The Result
- Processed 26 file(s), 12 of them cleaned, 0 error(s). Cleaned total of 106000 byte(s) in 0:00:01. Actually it likely took less than one second to process.
- To get the original file sizes, add the final size to bytes cleaned.
- I have separated the files containing information from those that do not for convenience...
- If your site contained the 12 cleaned images without being cleaned you would be hosting 106k of extra unseen data that a viewer would have to load.
- Note "blondes" which started as 73k was reduced by over 28k or approximately one-third by this process alone. I have seen many instances of watermark size exceeding image data.
- The size of the files tested is pretty much irrelevant and could possibly be optimized further for a particular use in a site.
- My experience has shown you are much less likely to have watermarks added by the good folks that use open source and distribute freeware than by commercial products.
I hope you find this information useful.
This article was originally published by CyberArmy.net in the CyberArmy Library.
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