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Size Matters! Posting images to the forum

Posted 26th February 2011 at 07:03 PM by Pano

OK, just because you own the latest Whizbang-3000 15 megapixel camera, does NOT mean you know how to use it.

Sure, you may take pretty pictures, but posting them here, or elsewhere on the web, requires some thought and effort.

See my comments below for more info. Click on "comments" down here.

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Size matters, but the size of what? No, not what you're thinking.

With images there are two sizes that matter

File Size
Image Size

File size is what concerns us most here, tho the two are related. For posting here, you really don't need a file size much over about 80-90 kilobytes - often much smaller. That's a size that loads quickly and yet is big enough to see what needs to been seen. Charts and graphs can often be 15K in size and yet large and clear - bigger isn't always better.

Posted 26th February 2011 at 08:07 PM by Pano Pano is offline

How to keep at or below 80K

That lovely camera you got for Christmas is chock full of megapixels, but we don't need them all here. Often the file coming out of your camera is 2 megabytes or more. Great for printing large glossy photos, awful for posting on the forum.

How to fix that?

You can change the resolution in your camera. Find a setting that gives you a smaller image, e.g. 640x480, 800x600, 1024x768. No need to go bigger. 800x600 and 1024x768 and good sizes for this forum. But there will be a second setting in your digital camera - Quality. You want a low quality setting, not high. Why?

If you intended to save, print or edit your photos, then high quality (and maybe large pixel size) is a good idea. But not for the forum. A medium to low quality setting is perfectly fine for the web. The difference seen on the screen will be minimal and it will load much faster.

So a smaller image size (fewer pixels) can lead to a smaller file size, but also a lower quality setting (more compression) can make the same image size smaller. Use both.

Posted 26th February 2011 at 08:18 PM by Pano Pano is offline

Pixels and conpression.

Why don't we need all those pixels? Cause our screens are not that big!

Very few of us are looking at this forum on a monitor that has a resolution of more than 1920x1080 pixels. Many are not even that high. And it's likely that your browser window isn't more than about 1200 pixels wide, maximum (all those sidebars and stuff eating up screen space).

So what happens when you post that pretty photo right out of your camera that is 3000 pixels wide? It does not fit! So.... we either have to scroll back and forth to see it, or rely on our browsers to resize it to fit in the window. Neither is good. Why not just make it a size that actually fits? Like 800 or 1024 pixels wide. That's all that will fit without shrinking or scrolling. Any larger is a waste.

But not all images that are the same number of pixels (800x600, 1024x769 etc) are the same file size. Why? Compression. If you are posting a photo here, it should be a j-peg (jpg). Jpeg is a compressed format, like MP3. Similarly there are different levels of compression. More compression = a smaller file.
The trade of is artifacts and some loss of fine detail, you've seen it, even if you don't know what they are. But we can do a lot of compression on an image and still have it be quite acceptable for viewing here.

So to get acceptable files sizes for posting we need to look at both pixel size and compression. Using them wisely goes a long way.

Posted 26th February 2011 at 08:30 PM by Pano Pano is offline

Reducing already large images.

What if you don't want to change your camera settings or you have existing images that are too big? You need software.

Digital cameras all seem to come with some sort of image processing software that includes resizing and compression tools. Learn to use it. If you don't like that software there are good, free image softwares on the net. irfanview and GIMP are two well known and well liked image programs. Stay away from MS Paint, it really does not do a good job.

Many modern OS have built in image resizing utilities. Try a right click (or whatever) on an image to see if there is a command there for resizing. Sometimes, that's all you need.

To recap: Try to keep your image file size to 80 kilobytes or smaller. Keep your pixel size to 1024 wide or smaller. Find a setting in your camera that will allow this, or do it afterwards with software.

Posted 26th February 2011 at 08:38 PM by Pano Pano is offline

	thanks for this pano - I have to say it drives me batsh$t when images are sooooo huge (especially so as we pay per Gb of bandwidth out here). I find it hard to understand why technically adept types like those who post here can't figure this out!
	Posted 26th February 2011 at 11:07 PM by aardvarkash10

	Yep, and thanks for posting that. I was going to mention those who pay for bandwidth, like our cousins down under. More better to have you mention it. Folks who read the forum on mobile devices are also bandwidth limited. I know many very smart audio types who just have no clue about images. I've given up wondering why and just try to offer guidance.
	Posted 27th February 2011 at 03:53 AM by Pano

	Yes, and I am one of those who didn't think about bandwidth when posting pictures. I have been posting pictures in the 200k range. I will repent! Bob
	Posted 27th February 2011 at 04:05 AM by Bob Brines

	LOL! Good for you Bob.
	Posted 27th February 2011 at 05:02 AM by Pano

Some may be aware that this is my pet hate.
I have started threads about picture size.

Having said that, my other pet hate are Photobucket and Imageshack.
Not just because of the image size.

For half the year, I read this forum while at work. (it is permitted ) I work on a ship with satellite "broadband" about 250kps.
Large photos take ages to download.
Those on filesharing sites are blocked by the company filters.
I would guess that I am not alone.

I frequently ask members to repost using the attachment facility, a request usually ignored !!

Andy

Posted 27th February 2011 at 03:02 PM by poynton poynton is offline

Thanks Andy. That's a new one on me, I had no idea that the photo sharing sites might be blocked. Yet another reason not to like them.

You're right, most offenders just don't seem to care. Several times a week I have to go thru the tedious exercise of downloading someone's huge linked images, resizing and compressing them in Photoshop and then uploading them as attachments.

The attachment option is the best, and it makes thumbnails of the attachments which really speeds up the page load. You only see the full size image if you click on it.

But there will always be linked to images. It's a fast and easy way to get an image on the page. Also good if the image does not belong to you, like one found on a webpage somewhere.

Posted 27th February 2011 at 03:31 PM by Pano Pano is offline

Quote:

Originally Posted by Pano

........ Also good if the image does not belong to you, like one found on a webpage somewhere.

In which case, should you be uploading it anyway. Copyright and all that......

As I said on the other thread ..

Quote:

I still thinkposting using photobucket or imageshack should be banned or at least blocked by the moderators.

Is this not possible for newbies still under moderation ?

Picture Removed - Too Large - Please repost using attachment

Andy

.

Posted 27th February 2011 at 04:37 PM by poynton poynton is offline

Updated 27th February 2011 at 04:44 PM by poynton

A couple additions & an important point that Micheal missed.

Last point 1st: When saving out graphs & charts, these should be in low bit (4-15 colours) gifs or pngs. This makes the images really small, but more imprtantly eliminates the noise (fuzziness) around sharp transitions (like text)

For the Macintosh, Graphic Converter is a good piece of shareware software for manupulating images.

And for either OS X or Windows probably best value in graphic software is PhotoShop Elements.

dave

Posted 27th February 2011 at 05:24 PM by planet10 planet10 is offline

Ditto the great value on Photoshop Elements. We have 2 copies here at home, 1 that came with the scanner, the other with the printer. Even if you have to buy it separately, it's worth it.

Yes, very good point on the gif and pngs formats. The formats of choice for graphics. They can make tiny file sizes and yet remain very sharp and clear. Rarely to charts or graphs need more than 8 colors. That choice can vastly reduce file size. I'm using PNG mostly now, as all modern browsers seem to support it.

Use JPG for photos - PNG for graphics.

Posted 27th February 2011 at 05:50 PM by Pano Pano is offline

For screen shots I use mwsnap and save as png. It is a great little freeware app and works on pretty much all windows platforms (even Windows 7 64 bit).

MWSnap - Free software downloads and software reviews - CNET Download.com

I used photobucket for my blog because you can't put attachments in-line... I guess another option would be to put the photo's in the gallery here at diyaudio and link them from there.....

Tony.

Posted 1st March 2011 at 06:23 AM by wintermute wintermute is offline

	Thanks Tony. MWSnap is great. I've been using it for awhile. Learned bout it right here on diyAudio.com. True about images inline, which are often handy. Over on Audio Circle I generally put the images in my personal gallery, then link to them.
	Posted 1st March 2011 at 12:47 PM by Pano

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