With JPEG when you upload a drawing that's heavily detailed onto your computer after scanning it, it loses a little bit of resolution and fuzzes out so you can't get the sharp clarity of the original and sharping the image with software dosen't really help much. However, they're a lot easier to download onto sites. With simple line drawings such as cartoon work that has very little detail, JPEG is fine for me.

With PNG (Portable Network Graphics), there is no degradation of the image when you upload it onto your computer. The image comes out as crisp and sharp as the original. The down side is that it's very difficult to download onto sites and galleries. Some of the drawings on my gallery are in PNG format and I had to make several attempts before I finally was able to download them. Dispite this difficulty, I'd much rather use PNG because of the higher quality over JPEG when it comes to my more detailed work. I just discovered using PNG format. I no longer have most of my original drawings that I have in my gallery. If I did, I'd rescan them in PNG.

Don't you need to have a graphics program that handles .png format to be able to view the files? Or, is there a viewer that the admin could make available? I haven't been doing too much work in this format, but I do know what you say about the quality is true. Its just that for postings on this site, there would have to be an ability of each and every member/guest to view this format. I believe this would be the only drawback in using it.

Eric

I use a camera to upload mine on .. but yoy do lose some clarify .. i do scan some stuff and make them as large as i can but i have crap soft ware so again it loses some of the finer detail ..

Rsine, yes PNG graphic files don't lose any definition when sent via email or posted to a site whereas JPG do lose a little each time you send them or post them.

Unfortunately the majority of forums prefer the JPG format and it tends to be the industry standard. On the internet, qualilty of imaging isn't perfect and I agree that some images are worse than others, but the blame of some of that lies with scanning or photographing the images, rather than the minute loss of image quality in transferring files.

I'm certain that jpegs do NOT lose image quality every time you view/send/post them.

I believe they do lose quality if you save and resave the same one, as it's getting compressed again and again, but no quality is lost if you're just sending the file to someone. It's the same as any other file in that respect.

Lizzeh, that's the way I understand it also. It's only with each re-save that quality is lost. Jpg and gif files are pretty much the standard for use on the web and since 72 dpi is just about the maximum viewing resolution (whether you upload at a higher resolution or not), it shouldn't really matter what format you use for posting on the web. It's actually the compression that distorts and affects clarity. PNG format is good for graphics with transparency since it is not limited to 252/254 colors like the gif format.

I normally save my work in either the .tif format or in the .psd format unless I'm uploading to the web then it will depend on whether there's any transparency or not as to the format that I choose. If I understand it correctly, the only formats that can be universally seen on the web are jpg, gif & png. Some bmp formats will also show but I believe that depends on your browser.

If you're just saving for yourself & not posting to the web, the "lossless" formats are tif, psd, bmp and I think, png. Various graphics programs have their own formats too but they usually can't be universally read by other graphics programs. And, most of the time, the above formats need to be enabled in your graphics program to be able to use them too.

As I said, it's usually the compression that's the degradation culprit in posting on the web but if there's no compression, the files are much too large for the average dial-up user to download comfortably. For universally quick viewing on the web, graphics need to be resized (I think the standard is no more than 600 pixels on the longest side) and compressed to a medium setting. Perhaps those people who are savvy with graphics programs will post their settings. I have PSP (Paint Shop Pro) and normally use a compression of about 20 for web posting. Since this is the program I use for resizing/compression, this is the only software I'm familiar with.

J

just a bit of explaination from someone experienced in internet graphics...

PNG is portable network graphic. It is built for fast internet transfer. It is the only image file type to support transparency, except for isolated GIF cases. In alot of respects, PNG is a good file type, it compresses to a small file, retains alot of pixel detail, etc. However, its use is not very widespread, and there are other, more technical problems with them (such as the limited palette). Often they are used in the place of GIF. Unlike PNG, GIF is not freeware. It is a file type that is owned by a large internet company, i forget which. Theoretically, everyone who uses GIF is meant to pay a royalty to this company. In reality, hardly anyone knows who they are meant to pay it to, let alone actually pay it. Quality-wise, GIF is only good for flat colour, so unless you do digital comics that have no gradients, dont use it.

JPG is a handy image compression algorithm that knocks out minute changes in colour of the pixels, usually smaller than the eye can see. However if the algorithm is set to a too higher efficiency rate, it can knock out detail that IS visible to the eye. Thus we run into the "my image looks ugly" paradox. JPG is also the most widely supported file type currently, and if you can not upload a JPG, you must ether be doing something really wrong, or you are in a really strange place on the internet. It is still the best file type to use when transfering a photo or full colour image over the internet, provided you set the efficiency rate to the optimal setting for your picture.

NEVER store images in a JPG format, as everytime you make a change to it and resave it, more detail is lost.

Lossless file formats do not try and be smart by cutting out detail, they leave everything in that they were given. In effect, these image types will not loose detail, and are the best archival format, with the trade off being they take up alot more space than compressing file types. These types are:
TIFF, RAW, BMP, PSD.

If you have photoshop, when you save the copy that you will post onto the internet, go to Image - Image Size, and change the resolution to 72dpi. This is the maximum resolution of computer displays, so its pointless to go any more, as it will just be wasting bytes.

Also, to make your images even smaller, go to File - Save for Web. Make sure you select 4-Up, and select your prefered file type. Now you have the option to select what compression you want, and check it against the original quality, and 2 other quality settings. Choose the quality that is the lowest you can go without loosing significant detail (it is up to you to decide what is significant).

Hope this helps.

Good advice and clarification on graphics from everyone here. Now I know a whole lot more about how to get the best graphic image out of my programs.

Thank you!