compress
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Written by guforosso
11 months ago Category: Feature discussion 5 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 ? |
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Written by jfalch
11 months ago 224 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. |
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Written by TTSneko
10 months ago 15 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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