Compressing digital photos

[albatross]

Can anyone suggest a program that enables the user to control the size of digital prints stored on a computer? Programs like Microsoft Office Picture Manager only offer three compression alternatives. So a 6mb picture can be reduced by clicking on either a) documents - which takes it to about 425kb; (b) Web pages - which is about 81kb; (c) Email messages - which is about 10kb. I also have picasa and pentax software but neither has any compression options. The ideal would be one that enables me to put in the kb figure that I require.

[photog]

albatros, I am not too sure what you are aiming for. If you reduce the size of the image the file size will be reduced, If you save in jpg the more you compress the image size the less colour information you will have and the worse the jpg noise will become. The amount the standard compression algorithms can compress will depend on the amount of detail in the image and remember that digital "noise" will be seen as detail and increase the image size.
Any information you throw away can not be recovered and I value my shots too much to spoil them in this way.
In any case HDD prices are now at an all time low. 1 TB of storage can cost about $120 AU or about $100 US. Why wear yourself out worrying about saving a few meg for each image?
Ron McDermott

[davemdsn]

Why do you need them reduced? How many photos are we talking about?

[Marc Sabatella]

It also isn't clear if you want to control the amount of compression only (eg, to create a hugely compressed and terribly quality picture that is still 2000x3000 pixels or whatever your camera creates), or if you'd prefer to reduce the reslution (eg, to to create a less compres,s higher quality picture that is only, say 1200x1800 pixels), or some combination. But once you figure out what you want, it should be a pretty trivial matter to get just about any photo management program to do a batch operation to achieve it.

[k0og]

Albatross,

I use FastStone Viewer for most of my routine processing (including very-useful batch processing). It reads Pentax (and all other) raw files, and you can interactively compress the files to whatever quality/size level you wish. You can find it at FastStone Image Viewer, Screen Capture, Photo Resizer ...

However, be aware that more compression equals lower quality of rendition!

I have found that selecting "Progressive" in the file-save dialog implements some significant additional lossless compression, and speeds up display of larger images (progressively) on web pages.

On top of all that, it is FREE!

-Joe-

Originally Posted by albatross

Can anyone suggest a program that enables the user to control the size of digital prints stored on a computer?
...

[rormeister]

If your mission is to simply 'resize' your images for purposes of using on a website like Flickr, you might look at the Free Irfanview tool. You can do bulk processing and save the new versions in new folders or the same folder with different filenames. It also has advance compression features for more professional results.

Can't say it enough, never overwrite your originals

[albatross]

Thank you for the suggestions. I should add that I have no intention of reducing the size of my photos because of storage space on my computer. It's that so many websites stipulate a maximum size for uploading (even this one!). At the moment I make a copy and compress that one as close to their size requirements as Microsoft Office Picture Manager allows - sometimes it is under my optimum size because it comes between the software options. Anyway I shall have a look at both IrfanView and Faststone. Thanks again for all your comments it has put me on the right track.

[Marc Sabatella]

Don't most sites that impose such limits automatically resize as necessary?

[albatross]

Originally Posted by Marc Sabatella

Don't most sites that impose such limits automatically resize as necessary?

This site state that the file size limit is 1.46MB. When I tried to upload a 6.13MB picture it bounced back so I made a copy to document size (352KB), there is no other compression option larger than that in Picture Manager, but that at least worked. I would prefer to have the option of selecting 1.46MB as the compression size to keep it as large as possible. Is there something that I am not aware of?

[Marc Sabatella]

I've never heard of Office Picture Manager, but as I said before, any decent photo management program would give you the ability to resize a picture however you like. But rather than simply pick a size in MB, you'd be better off deciding what resolution and quality you want. When posting to the web, there's no reaosn to make a picture bigger than full screen; typically 1000 pixels on the longest side is as big as you need. Make it that size, use relatively low compression, and file size shoud come in well under 1 MB.

[Arpe]

Anyone tried this for compressing photos - supposedly lossless, like zipping, but for photos.

[brecklundin]

for websites, remember to do a save as and change the DPI to 72 which is typically fine for the web. That alone will reduce the size of your file.

And yup, many, if not most sites which impose size limits, especially forums, will not automagically compress and/or resize your images to fit within their limits. It is a lot of server overhead for those sites so they leave it to the user to figure out how to do it themselves.

On many sites with limits, those limits, in terms of file size not image dimensions, only apply to images you upload to their site. If you want you can link to a file of any size hosted on your own server or hosting service. Just remember almost all sites use a max longest side of 1024px so give consideration to that and for the huge number of users out there with lower resolution displays. Also if using larger file sizes, remember also, even in the US, a very large portion of users are still either on dial-up or have what is so-called 'broadband' of just 768k download speed...I try and keep file under 300k in forums.

It is just a learning curve...good luck...