posted on January 5, 2001 07:17:14 AM new
There was a short mention here recently of PNG graphics files as an alternative to JPGs. PNGs support 16 million colors, but are "lossless" which means PNGs don't lose quality due to compression like JPGs.
Since there are some issues regarding licensing and GIF files, PNGs are designed to be a substitute. Reduce the number of colors to 256 to create smaller PNG file sizes.
PNGs are currently supported by MS Internet Explorer and Netscape, though not yet fully supported. PNG images themselves support many (256 or more) levels of transparency so they can be used to create composite effects. (GIF files offer only two levels of transparency - ON and OFF.) Most browsers don't yet support transparency for PNG files.
Below is a PNG file from one of my current auctions. The quality is very good. (I enhanced the photo by removing the background and adding a very subtle drop shadow.) The file size is 172 Kb, which is large, but depending on your item, you may find this kind of higher-quality image useful.
posted on January 5, 2001 07:31:24 AM new
Looks fine on Netscape 4.61.
How do you remove the background in your pic? I have ArcSoft Photostudio and Paint Shop Pro and haven't been able to figure out how to do that. I think it makes certain items stand out beautifully.....
posted on January 5, 2001 07:59:59 AM new
Misconception:
You say PNG's "are lossless which means PNGs don't lose quality due to compression like JPGs"
JPGS lose very little quality on compression the first time (unless you overdo it) ... where they REALLY lose it is if you edit, compress, and save the JPG repeatedly. If you take the few seconds to run an image converter on the original images and make them into a TIFF for editing you will have no problems. Just save as JPG for uploading.
The extra size of the PNG is a SERIOUS drawback when you want the auction to load FAST. A well-edited JPG with carefully selected compression will be 1/5th the size of an equivalent PNG, which means that I can show several JPGs for the bandwidth of one PNG.
This is a 22KB JPG, resized edited and compressed from a 640x480 JPG.
And this one is a whopping TWENTYTHREE KB.
I can go from raw digital photos to the finished JPG in under two minutes ... definitely not a hassle.
posted on January 5, 2001 08:14:15 AM new
Boy, Abacaxi, are you mad at me or something? Or am I just wrong today?
I am a cable user so file size isn't really important (to me). I don't use PNGs for large eBay images, 'just wanted to point out the option (this is a trade-off: file size vs. image quality) that is available. To my eye, PNGs are much better. If I was selling the Hope Diamond, I would want to use the best quality output as possible!
If you wanted to include a small photo of yourself in your ad or About Me page, say 100 pixels square, a PNG might be a better file type to use because the quality of the photo is better, and the difference in file size may be very small.
posted on January 5, 2001 08:27:28 AM new
Toke, Here's how I did it. Photographed the black shirt hanging on a white wall. Then selected all the (white) parts of the image that didn't belong to the shirt. (Everything but the shirt is selected.)
Then, I just chose "Cut" from the Edit menu to delete the area surrounding the shirt.
You may need to create a transparent layer first under the layer with the shirt. This allows you to do add some filter effects.
After I cut or erased the background, I inverted the selection so that the shirt was selected. Then I applied a very subtle drop shadow to the edge. Then I resampled the picture down to maximum 300 x 400 pixels for eBay's photo hosting option.
The best selection tool I've found for this job is Adobe Photoshop's Magic Wand tool. Adobe PhotoDeluxe also has a very similar Magic Wand. PNG files support multiple levels of tranparency. But browsers don't support PNG transparency yet. Once MS and Netscape get up to speed, PNG files will be used to create superb semi-transparent (shadows, fire, smoke, etc.) effects.
(edited to add: This photo was acquired directly from my Kodak digital camera. The image started as in Kodak's proprietary FPX (Kodak FlashPix) format, so there was little loss in quality throughout the process.)
posted on January 5, 2001 08:36:22 AM new
Thanks, twinsoft...I'll see if I can adapt your process to one of my programs. I'm assuming that you had to outline the shirt to select the background, right?
posted on January 5, 2001 08:53:50 AM new
Toke, there's no need to draw an outline. Use the Magic Wand to select all parts of the image you want to erase. Then select "Cut" from the Edit menu.
Take a look at PhotoDeluxe's Magic Wand.
In addition to setting a threshold/sensitivity for the Magic Wand tool, it also has two variations. You can also add to a selection or subtract from a selection. This makes it easy to get just the right pixels selected. Also helps to have a highly-contrasting background.
posted on January 5, 2001 09:18:12 AM new
toke -
There will be a small amount of loss in the editing, but not much. The loss really happens when you compress to save ... image information is discarded to make it smaller and you can't get it back.
As a matter of habit, and as a safety measure, I NEVER edit original images, so running the convertor to get TIFF for editing also makes me a copy to edit. On that image I can save between edits (a good idea, especially if you are getting rid of backgrounds and doing other time consuming steps) with no loss of quality. The sugar bowl
Twinsoft ...
Yup! We seem to have some serious diferences of opinion. I am ACUTELY aware of bandwidth and how to make fast-loading pages. Many major corporations have a size limit on the amount of text and graphics any page can have, and it's under 100K for most of them. If I were selling the hope diamond, I would have a LINK to the closeups with the file size mentioned.
The idea is that no matter what browser the user rides in on, the merchandise should be immediately visible and load fast. I'm not goping to insult a potential buiyer by telling them they have to download and install WhizyBrowser7.3 for the privelege of viewing my stuff. I don't care if they are using Netscape 1.2 ... it will show up for them too.
posted on January 5, 2001 09:31:09 AM new
Thanks, Abacaxi. I have a Mavica and save my original image on the floppy until I'm happy with my work. I've had to redo many times after a giant screwup with editing!
It sounds like an image converter is a good idea. Can you recommend a decent one that I can download?
posted on January 5, 2001 09:40:06 AM new
Question regarding TIFF vs. JPG:
After reading suggestions here, I have tried saving the same scanned image in both TIFF and JPG format, doing some minor editing (lightening, cropping) and re-saving each image in JPG format. I don't see any difference in the final images- is this typical? Does this question make sense?
posted on January 5, 2001 10:09:19 AM new
toke -
The best FREE software collection on the net: http://www.nonags.com and it's all virus-checked and has no popups that annoy you begging for monty in the freeware section.
Graphics are at http://nonags.com/nonags/grapht32.html and I suggest XNview for a convertor and ImageNavigator to organize and rename batches of graphics. I've used them both for months at work.
Best FREE photo-editing program is GIMP. Big LINUX-origin thang, but wih a really good port to Windows. http:/www.gimp.org/
mrpotatoheadd -
It's when you re-open a JPG for a bit more editing, and save it again that you see the image quality decrease. The more you open and save it, the worse it will get.
posted on January 5, 2001 10:15:36 AM new
abacaxi-
Ok- that explains it. I usually only edit once and save. So it appears that, in my case, there is no benefit in saving the original scan as TIFF over JPG.
posted on January 5, 2001 10:30:26 AM new
mrpotatoheadd -
True, except for the times when your graphics program crashes and wipes out the image, or you decide it needs a bit more tweaking.
Abacaxi, I do consider my customers in choosing which graphics to use. Many customers appreciate bigger, clearer photos, even if they have to wait a few more seconds.
Oh, I know that strictly "by the book" web pages shouldn't have more than 100 Kb of graphics. I'm not claiming that PNG files are the greatest thing since sliced bread, only that in some cases they can be useful. (Remember, they're supposed to replace GIFs, and at 256-color depth, the file sizes are very close.)
I always try(ed) to keep my graphics below 70 Kb. Eventually we're going to have to come in from the Stone Age. There's no point in crippling an eBay ad just so some slowpoke die-hard with his trusty 2400 baud modem can get a good look too. If someone is going to be browsing the Hope Diamond at eBay, they'd better do it on a T1 line!
posted on January 5, 2001 01:11:45 PM newabacaxi: See, that's the problem with my Sony Mavica FD-85. You talk about starting out with "raw digital photos" before you do any editing. Unfortunately, the Mavica FD-85 stores all images as jpegs to start out with, and they're significantly lossy. Even if I immediately convert the image to a tiff or a pcx before editing, the loss has already occurred. The most I can do is prevent the image from degrading any further.
I do love my Mavica. It has many nifty features, including a built-in flash with variable brightness level, an excellent macro feature, a great optical and digital zoom, settings for extreme low light photography [I've been able to shoot outdoors without a flash as long as I can keep the camera steady], etc. Plus, the image resolution is fantastic and I can shoot up to 1280x1024. It even has a settgin to automatically adjust the color for indoor photography! But I just wish I could somehow prevent it from automatically saving the images as lossy jpegs. I know that the reason it does this is to fit a reasonable amount of images onto a single floppy disk, since it has no built-in memory, but there are times I'd rather get 1 or 2 high quality images on a disk rather than 30 not so great shots....
Barry
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The opinions expressed above are for comparison purposes only. Your mileage may vary....
posted on January 5, 2001 02:11:59 PM new
godzillatemple -
Check the settings ... you have multiple choices:
On the FINE setting the initial image is not a compressed JPG, it's just a JPG. That has almost no loss at all. The "STANDARD" setting compresses the output somewhat,
For recording modes: NORMAL is uncompressed and the EMAIL recording mode really squishes it. Maximum squish (and minimum tolerance to editing) is Standard/EMail.
Image size: 640x480 or 1216x956 (?)
Taking pictures of the SAME scene at the same zoom, varying the settings made the image size vary from 70KB (smallest, maximum squish) all the way to 349KB (largest, nimimum squish). Try the higher settings and see what happens.
posted on January 5, 2001 02:47:52 PM newabacaxi: Methinks you have a different model in mind. The FD-73 perhaps? The FD-85 doesn't offer a choice of "Fine", "Normal", etc. Instead, you simply choose the size of your image: 640x480, 800x600, 1152x864, etc. There is also a special "email" setting which takes a 320x240 picture.
As far as I can tell, however, all the various options use the same level of compression. The larger pictures are certainly, well, larger, but they seem to be just as lossy. I did try taking photos using the larger image size, but I still had to shrink them down for my use and things got a bit jagged.
Maybe it's the type of items I am trying to photograph? Your average pocket watch has a lot of straight lines, whether it be the hands or the numbers on the dial, and this is where I tend to see the loss the most. These are also the parts that look really crappy when I try to reduce the image sixe from a larger version.
Barry
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The opinions expressed above are for comparison purposes only. Your mileage may vary....
posted on January 5, 2001 03:58:41 PM newabacaxi...
I just had to drop in and thank you for the Nonags site. I've already loaded two programs...it's like a candy store! I had no idea all those goodies even existed...
posted on January 5, 2001 04:25:54 PM newabacaxi: Yeah, a tripod would probably be a good idea. I'm taking extreme closeups, though, and I haven't had much luck using a tripod. Practice, practice, practice...
I have used an "unsharp mask" and, while it certainly makes everything look, well, sharper, the blotchy, lossy areas still remain....
Barry
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The opinions expressed above are for comparison purposes only. Your mileage may vary....
posted on January 5, 2001 04:45:46 PM new
Barry...
There must be something wrong. I take mine in standard mode and have never gotten those blotchy, lossy areas you speak of. Have you tried new floppies?
posted on January 5, 2001 04:48:00 PM new
PNG's are useless for eBay right now. Not all web browsers support them. At least 10% of bidders wont be able to see them. No WebTV people as far as I know.
Also PNG doesn't even really solve the problem it was orignally created to. Getting rid of GIFs. We all hate GIF because UNISYS is a bunch of greedy bastards. Ever wonder why you cant use a gif image as your eBay Gallery image? Because eBay wont pay UNISYS the license fee.
So anyways that was the main reason it was created, to be a better and free version of GIF.
Of course when they started it ads weren't a big thing yet on the net so the last time I looked PNG didn't support annimation! And 99% of what gifs are used for today is for the animated banner ads we see on every web page.
So to make it short, hardly anyone uses GIFs anymore anyways, and those that do use them for Banner Ads, which the last time I checked PNG doesn't support. And the fact that the UNISYS patent license is set to expire at the end of this year PNG may be set to wither away in the internet wind...
posted on January 5, 2001 04:57:48 PM newToke: What model mavica do you have?
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The opinions expressed above are for comparison purposes only. Your mileage may vary....
posted on January 5, 2001 05:02:11 PM new
I have an FD71. I wonder if your trouble is the shine on your watches. I have a very hard time with photos of shiny things like silver...except in extreme closeup. The closeups turn out fine. Glare gives me fits when I get farther away....
posted on January 5, 2001 05:39:31 PM newToke: What can I say? the FD85 is a different model. It doesn't have a "quality" menu. Instead, you select "image size" under the "File" menu. And all images are stored as jpegs, regardless of the size.
And I don't think glare is the problem. It's simply that the images are compressed in order to fit 30+ on a floppy disk, and are therefore a bit more lossy than I would prefer....
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The opinions expressed above are for comparison purposes only. Your mileage may vary....
