distal-attribute
distal-attribute
distal-attribute
distal-attribute

compress

User, date Message
Written by guforosso
2 years ago
Category: Feature discussion
6 posts since Fri, 17 Dec 10
i have insert image into db use a compress function
set ...field=compress(image_binary_data) to display img i use uncomprss(field) AS img, the db size is reduced file size at 1% to 3%
to display image/fileld is possible to add feature compress
and/or decrypt ?
Written by jfalchMoney, Euro
2 years ago
389 posts since Sat, 17 Oct 09
images (e.g. .jpg, .gif) are often stored as files that are already compressed internally; compressing them again will yield only a very small size change, as you have observed.
compress() will usually make data smaller, ie is a compression method built into mysql (usimg the zlib algorithm); it only doea not work well on already pre-compressed images.
Written by TTSneko
2 years ago
41 posts since Thu, 19 Jul 12
I know this is an old post, but a friend came up with the same question not too long ago:

Normal JPG images contain a normally completely useless 'add-on' which can be easily removed: the EXIF information block. Depending on size of the images, the removal of the EXIF info yields far better results than *ANY* compression, in my case tons of images the range of 25-30kb were left at roughly 8kb each (one third of the previous size!).

Google for tools that allow batch functions in this matter. I have Win7-64bit and still use the CMD-line (DOS-box) tool "JHEAD" as it works in batches (even though I mostly use it as button function from my file manager) ...

And no, dropping the EXIF data does not ruin or otherwise render a JPG file useless; the files are not even 'written' (re-compressed) again during the process, hence there is also no further quality loss.
 

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