This can be applied to any digital pictures but I am going to be using it to reduce the size of coin images (especially for the grading challenges) on the website. Some people who run coin auctions on Ebay could use to learn this tip also.

The link is:

http://www.netmechanic.com/cobrands/zd_dev/accelerate.htm

Yes, you can do this in most any graphics program but the problem I have always had with using software is that it is often hard for me to tell how much quality has been lost at a specific compression level.

On the site above, you put the internet address of the photo you want to compress in the input box and then click Optimize. (Note: choosing JPEG Only will greatly help in reducing image size for other types of images such as gifs.) The page that appears will give you a bunch of compressed images on the screen.

Then, through the evil magic of javascript, when you put your cursor over the compressed image, the regular image toggles in its place. What this means is that you can toggle back and forth between the original and each compressed image to see how much you are losing in quality by just running your mouse over the image.

By going back and forth quickly, you can easily tell which very small patches of the image are changing and how much quality loss you are experiencing do to the compression. I find it really helps in getting a nice picture that will be much easier for people to download. It also tells you next to each picture the compression level and what the new file size would be.

After you decide which image you want to use, you can click on that image and a new page will open up. You can save that image to your hard drive (typically by right clicking on the image and saving it). You can then replace your old bloated image with the new slimmer, sleeker image. Note: It is always a good idea to keep a copy of the original uncompressed image for backup purposes.

For the grading challenge a week or so ago, it took two images (each in the 600x600 pixel range) at 450k total size and got them down to 115k total size with no loss of quality apparent on the screen.

I could even go a little further if I was willing to lose a little bit of quality for something like the pictures in the museum. I could easily get them under 100k total and still have good looking pictures.

--------------------

|| The Stujoe Collection || Digital Photo People || Stujoe.com || NumisLinks || NumisWiki ||

Note to the note: this is not entirely true. JPG or JPEG is developed specifically for photographs. If you take GIF images with larger areas of the same colour, like e.g. screenshots the JPEG compression will fail and create larger files than GIF would do, and also at a worse quality....

Would that be true for any full color coin images? I have never seen it happen when I have used it for the coin pictures.

When you're converting GIF photographs, it will reduce the size, as you're working on a photograph. What I meant was things like screenshots from e.g. a page in CoinPeople, e.g. this page. The large blue areas in one and te same color withthe lines in different colours, that stuff is difficult for JPEG and will result in ugly, blurred stuff that is larger than a GIF.

I am told by a software engineer friend of mine most people do not know anymore what a bitmap file is
I save everything in bitmap file with no quality loss
for coins I use jpeg for stockcharts I use gif ( graphic format )
attached the post in jpeg

Attached is a gif which by the board has been jpegged

Omg no. There is still bit loss in .BMP file. The only way you can avoid the most bit loss is if you save it under .png format. .gif and .tiff still don't do the job efficiently, as .gif is only supposed to be used for animated images and .tiff is supposed to be for vector images. .bmp is supposely bitloss, but that only works efficiently when the colors are not too complicated as in high resolution colors.

Now, please do me and you a favor, which is to download a software called IrfanView, still currently free. Link: http://www.irfanview.com/

This software is powerful enough to crop your images, do some of the easy resizing, and converting one format to another and you are even able to choose the reduction %.

Normally what I do nowadays for instance is when I get images from my scanner, I save it under .png, and even when I edit them, I still save it into another file as in .png. It is only when I want to publish my pictures online do I save them as .jpg and upload them. I rarely compress my .jpg files, at worst, around 80%, no less.

Of course, you can argue how much space it can take, but for god christ, how much space can it possibly take up, including all the edited files etc? Mine usually takes up to 7-20mbs per coin because I keep every single file, including raw files or else it would be around 4mb or so. If you run out of space, you do have something called cd-burner or dvd-burner, where you can get medias for less than 20 cents or 80cents respectively. Storage is just not a problem.

I agree that there are web sites out there where you can crop, scale down or up, invert, etc. and they are free. Also, there are many out there that cost only about $15 or so. I have many of them. I save all photographs in .jpg and with the most basic photo program I can crop, reduce, enlarge, etc any photo. I have actually thousands of photos on one of my computers that were shot with about 2 megapixels. I also have thousands shot at 3, 6 megapixels. I usually back them all up on a CD. With 2 hard drives in computer #2 and one with 200gigs I don't worry about space. I have tried changing photos from .bmp to .jpg or to .gif or many of the other options available but can not see any reason to do this. With a decent photo program you can crop any .jpg to the smallest spot on a coin if that is something you want to do. Since the greatest amount of digital cameras use the .jpg format, I can not see any reason to modify those.
As the old saying goes, let sleeping dogs lie.