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I am completly imaging illiterate.

I have beenlooking at my camera manual and it allows me to set recordin pixelsand compression. I thought setting the compression was stting the dpi - but I just did some research and found out that is not the case. I think I now have a general idea about what the compression is.

Quesion - when I set the recording pixels - how does this relate to DPI.

I have a really simply imaging tool that came with an HP printer I had. I like it becuase it is simple. It allows images to be resized. You can set the size by setting the width and height in either pixels / inces etc. You can also set the dpi. Just out of curiosity, I download GMIP (I don't expect to ever do much with it). When I display an image that I took with my HP software and then display the same image in GIMP - for some images the 2 different softwares do not show the same DPI.

What is it acutally showing - it is the dpi that it thinks the photo was taken at - or is in th defualt setting for saving.

When I set the Recording pixels on my camera what am I acutlay setting?
it has setting for :
Large -- 7M - 3072 x 2394 pixels
..
..
..
Small - .3m 640 X480 pixels

Is the above the total number of pixes?

DPI x number of inches = total pixels

For the picutre I took, the camera recording pixels was set to Large
If I display one of my images in my HP software
it shows the DPI as 180
show the width: pixels as 3072 inches as 17.07
height: pixels as 2304 inches as 12.8
( 12.07 * 180 = 3072.6 and 12.8 * 180 = 2304)

If I display the same image with GIMP
it shows
pixel size 3072 X 2304 (sams as with he HP softwaree)
resultion 72.0 X 72.0 (different from the HP software)
for size in inches it shows: 42.667 X 32.000
(42.667 x 72 = 3072.024 amd 32 * 72 = 2304)

Where did HP software get the 180 value and where did the GIMP software get the 72 value?

How do I know the DPI they are taken at. What DPI is my camera actually using?

I am so confused
It's driving me nuts!!!

Fay

fay47 wrote:

Quesion - when I set the recording pixels - how does this relate to DPI.

Just out of curiosity, I download GMIP (I don't expect to ever do much with it). When I display an image that I took with my HP software and then display the same image in GIMP - for some images the 2 different softwares do not show the same DPI.

What is it acutally showing - it is the dpi that it thinks the photo was taken at - or is in th defualt setting for saving.

When I set the Recording pixels on my camera what am I acutlay setting?
it has setting for :
Large -- 7M - 3072 x 2394 pixels
..
..
..
Small - .3m 640 X480 pixels

Is the above the total number of pixes?

DPI x number of inches = total pixels

For the picutre I took, the camera recording pixels was set to Large
If I display one of my images in my HP software
it shows the DPI as 180
show the width: pixels as 3072 inches as 17.07
height: pixels as 2304 inches as 12.8
( 12.07 * 180 = 3072.6 and 12.8 * 180 = 2304)

If I display the same image with GIMP
it shows
pixel size 3072 X 2304 (sams as with he HP softwaree)
resultion 72.0 X 72.0 (different from the HP software)
for size in inches it shows: 42.667 X 32.000
(42.667 x 72 = 3072.024 amd 32 * 72 = 2304)

Where did HP software get the 180 value and where did the GIMP software get the 72 value?

How do I know the DPI they are taken at. What DPI is my camera actually using?

Fay, I don't quite understand the different dimensions in the 2 imaging software applications, but my guess is that the hp software does a dimension compression (perhaps there is a setting for this somewhere in the hp software and you are getting a default that can be changed?) without resampling that gives you smaller image dimensions in inches but retains the image resolution by increasing the number of pixels or dots per square inch (dpi). You still have the same number of pixels in the total image. In gimp, I would think you are getting what your camera actually outputs, which is typical - 72dpi for jpeg images, but with much larger image dimensions. This is the dpi used for web viewing.

The term dpi refers to "dots per inch." DPI is often synonymous with ppi or "pixels per inch." It is a standard way of describing an image's resolution. When printed, an image with a high resolution contains more pixels, or dots, than an image with a low resolution. For example, a 1-by-1-inch image with a resolution of 72 dpi contains a total of 5184 pixels (72 pixels wide x 72 pixels high = 5184). The same 1-by-1-inch image with a resolution of 300 ppi contains a total of 90,000 pixels. Higher-resolution images reproduce more detail and subtler color transitions than lower-resolution images. 300dpi is typically used for printing images.

I know you like things to be simple. But I will tell you that you will enjoy your photography much more if you take the time to learn to use GIMP. It will have the resizing options you need for web viewing, and will have options that make it easy for you to change the dpi of your photos to 300dpi for printing. You would typically convert them to tiff format at 300dpi with smaller dimensions - typically the dimensions you want to print. With your camera, you can save and print photos from wallet size or smaller all the way up to 19 X13 inches - I'll give instructions in another post if you can't figure out how to do that. Jane can probably help too, since she uses GIMP and I don't. You always want to use the Largest recording pixel setting in your camera to get the best image resolution.
_________________
Repa

Older than dirt!

Repa,

I really doubt I'll be doing much it the way of editing - mainly resizing and maybe croppitng.

If I undersnat, if I am going to put a picture on the web or e-mail i need to leave it as .jpg but if I am going to print I need to convert to .tif - is that correct?

Also, did I understand you that most cameras out put at 72dpi? I could not find a setting for that on my camera so I guess it is pre-set?

I may try taking another picture and re-sizing to see if I can get closer to the recommended size.

Thanks,
Fay

Ok, I took another picture and uploaded to the computer. I used gimp to resize - it was set at 72dpi and I changed the width to 650 and it set the height to 488. I tried saving at different qualities. At 75 perecent the file was 95KB , at 65 percent it was 78 KB and 55 perecent it was 68KB.

Is is normal to have to reduce the quality this much? Should I be changing the size instead?

Fay

fay47 wrote:

Yes, it's normal. The difference in quality on your computer monitor is barely discernable to the most critical eye, and the normal viewer won't be able to tell the difference. If you have a sliding bar for your quality adjustment that you can adjust and see the change in file size while you are doing it, that makes it easy to set the recommended file size. Look for a "save for web" in GIMP - I don't know if it has it, but Jane should know. She may be able to give you some pointers on how to use GIMP to get the file size correct. Jane?!!! help!!!!!

Just to give you an idea, I've gone as low as 19% to get the file size down to 60KB on occasion, and you are hard pressed to tell the difference on your monitor. Now, if you did that for a print, well, I hate to see what it would look like! And yes, you want to print .tif files, not .jpg. You can upload images in following formats: .gif, .jpg, .png, .bmp. File size limit is 4MB, but as I said before, we try to use 60KB for dial-up users, although it isn't critical. Don't worry if your files are a little larger. It is only if you enter the Photo of the Month contest that the guidelines need to be adhered to as larger files cannot be uploaded there - the upload will fail.
_________________
Repa

Older than dirt!

Reap,

I did not see a save for web but maybe I am looking in the wrong place. There is a sliding bar for the quailty adjustment. Underneath that there is a place to show file size - but it is telling me unknown. Don't know why that is.

Thanks for the help,
Fay

here's some information that might be helpful to you:

http://lists.xcf.berkeley.edu/lists/gimp-user/2006-April/007853.html

http://archives.free.net.ph/message/20071103.003626.5b853a34.en.html

If you enter "gimp save for web option" in the text box at google, you'll find other articles about GIMP and save for web.
_________________
Repa

Older than dirt!

Repa,

Thanks for the information. I did do the search you suggested but did not spent too much time looking at it. At least part of it seemed to be talking about a plug-in for the save as web. I didn't spent enough time to know exactly what I need to get or where.

I also took a brief look at the other links you posted. I did resize first and then did save as and changed the quality. I am wondering wheter it is better to take the quality down really low or to make the picture smaller than the max size first.

Thanks,
Fay

Well, you can reduce the photo but you have to do it with resampling or most imaging software will increase the pixels/inch to keep the total pixel count in the image the same. And, when you do that, you lose some clarity (focus), but you can use the sharpen tool or unsharpen mask to get most of it back.

You might want to think about cropping your photos if your subject is surrounded by a lot of background - that will reduce the file size as well as the dimensions. But, as I mentioned before, the difference in low, medium, and high quality photos viewed on your monitor is not that great - it only makes a big difference when it comes to printing.

If you decide to make your dimensions smaller, I wouldn't go below 400 pixels in height, or the photos will start to become too small for clear viewing, especially for those of us in advanced years! Laughing

But, as I told you before, it isn't that big of a deal for the photos posted using "Add image to post" because only the thumbnail is displayed in the forum, which is always small.
_________________
Repa

Older than dirt!

Repa,

Thanks for the input. I think it is all a bit much on my poor old tired brain. Laughing

If I can just figure out enough to to post a occasional image - that will be enough for me.

Thanks agaom for you help

Fay

Fay,

If Gimp is too complicated for you... check this onliner

http://www.freepowerboards.com/geeksmore/geeksmore-post-13880.html

Another thing... Sandra suggested you get a Photobuckect account. I am new to it, but Jane and Rike uses them for awhile now. At Photobucket you can also resize your images and it gives you the thumbnail feature, which when used instead of the using the whole view, is less heavy on our forum threads.

BTW... don't you have Microsoft Office Picture Manager?
_________________

"Spirituality is not religion, religion divides people. Believing in something unites"

Sam,

I'll have to check this out sometime. No I don't have Microsoft Office Picture Manager - not even sure what it is.

You said Photobucket would let you use a thumbnail featue - isn't that what we do at postimage (which I haven't used much either), or is there a difference?

Fay

fay47 wrote:

You said Photobucket would let you use a thumbnail featue - isn't that what we do at postimage (which I haven't used much either), or is there a difference?

Yes... both services gives you the thumbnail feature to use in forums... in fact most image services provides the thumbnail feature.

Reason being that it is lest heavy when opening a thread

Having an account with images services like ImageShack or Photobucket gives you control on your images... like what you can delete or not. With Postimage you do not have this
_________________

"Spirituality is not religion, religion divides people. Believing in something unites"

Sam,

Can you set something like a passoword for the images?

Fay

fay47 wrote:

Sam,

Can you set something like a passoword for the images?

Fay

I don't quite understand this question Fay

If you use Photobucket or Imageshack (Online Image Services) you create an account to use their services... therefore you do get Password protection just like if you are to use an email account like Hotmail, Yahoo or Gmail.

... with Postimage you do not... and you have no control on your image once you uploaded it to Postimages services.

Now, you guys really have to understand how secure your images are when using these services.

I must let you that Repa & I have been having LONG conversations on this topic from time to time Rolling Eyes

The bottom line is... on the Web your images are "not safe"... depending on your budget & software you can have security on images.

If you don't care for your images but you do care for your security we are providing you with our best knowledge of information on the topic here, as we are interested in the same
_________________

"Spirituality is not religion, religion divides people. Believing in something unites"

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