If there is anyone out there who can educate me on scanned slides and resizing in Irfanview. I get my slides scanned at 400dpi and put on CDs. I figured out how to resize when looking at the slide on my computer, but I've noticed that when I put them in emails, etc as attachments that the size I'm seeing on my computer is not the actual size. For example I download a file and resize it at 300dpi and 920 on the longest side and it looks about 8x12 on my computer, but when received by others is 1.5x2.5 inches. Also, how can I get a 125kb file at about 680x420 (approx.) using these scans...the files always seem too big according to the file size (MB and KB)on my screen...so I resize them to lower the kb size and I think I'm ending up with tiny photos when sent online. Is this not possible? There's something I'm missing or don't get. Hope someone can help. P.S. I'm very low tech, and don't have photoshop or any graphic capabilities. Just the CD scans and viewing capability with the Irfanview. Also, when received by someone else, if they have photoshop, can they resize on their end?
Thanks in advance,
Cynthia Spence
Posted by Dan Borzynski on March 22, 2007 at 1:59 PM
If the recipient has PS in any form, they can resize without any problems at their end.
For the resizing, I have to admit that I am not familar with the program, so I am going to take some guesses as to what you can do. If it has an option to resize (which I have know idea if it does), and you want to resize for web use, computer use, or e-mail browsing, use that. Resize as follows:
dpi: 72
longest side (which ever that is) 680.
Photoshop will make you do the dpi selection first, then the longest size. If you reverse the order, the file gets really teeny. It is a quirk, but you get use to it.
There may be an option to constrain proportions. Basically, you don't want to start with a file that is, say 1200 by 1800, resize one side to 680, and then not have the other side resize, so you get something like a 680x1800 image.
For saving and file size:
Look for an option called save as, then look for a jpeg saving option. Ideally, you'll get a couple of saving option, small, medium large, or maybe a corresponding number. PS lets you pick numbers between 1 (small file size) to 12 (huge file size). You'll need to play with that to get the sizes to a number you are happy with. Lots of details will always give a larger file that one with little detail, so using a blanket resizing of say, medium, will give different results.
With regards to the different sizes on screen from what you see and what the viewer sees, it sounds like that might be partly the software being used to view the files. Assuming that the file is the same number of pixels on each side, and it is viewed at 100% (or any other consistent percentage), it should appear at the same size on different monitors. I have, off of the top of my head, 5 ways of viewing images on my home computer, and they all come up with different sizes when viewed on the screen. Once they are brought up to 100%m they are the same, though.
I have know idea if any of that helps, especially since I am not familar with the software.
Actually the term "dpi" is ambiguous here. You need to distinguish between the input dpi (scanner) and the output dpi (display/printer).
The scanner resolution (dpi) determines how much information the scanner will extract from the film and how many pixels will be in the resulting image. If you need to resize the file for screen display only, then the output dpi doesn't matter. The only thing that does is the pixel size.
I'm also not familiar with Irfan but look for a function that will allow you to set the image dimensions in pixels.
Guy
Posted by Russ Carlson on March 28, 2007 at 8:16 PM
Cynthia, the dpi is dots per inch, and represents the number of pixels. If you are scanning at 400 dpi, each inch of the slide is converted into 400 pixels going across. So the width of the image being scanned will determine the number of pixels in the saved image file. Now when you view on a computer screen, the software can display it in a number of ways. Most screens display between 72 and 100 dpi. So if you view an image that is 400 pixels wide (one inch from your scan) it will appear as 4 inches on your screen. On a lower resolution monitor, it will appear a bit larger.
Now let’s consider the images you have that are 920 pixels wide. If you set these to 300 dpi images, their actual size will be just over 3 inches wide. Again, what you see is dependent on the software you are using and perhaps how the preferences are set to display. If your images will be mostly viewed on a computer screen, such as in an email program, try setting the image resolution to 150 dpi, or even 100 dpi. The image will look just about the same on screen, but larger.
Resizing is fairly easy with most image processers. And although you can actually make a picture larger (more actual pixels, not just changing the dpi) than it was, the results are often not too good. Changing the dpi settings only affects the display size, though.
Russ
Posted by Mark Stahlke on March 28, 2007 at 10:13 PM
Hi Cynthia,
I have IrfanView installed on a USB key and I just took a quick look at it. I think I see what you need to do.
To resize:
1. Select Image->Resize/Resample from the menu. This brings up the "Resize/Resample image" dialog.
2. Make sure "Preserve aspect ratio" is checked.
3. In the "Set new size" portion of the dialog type in the dimensions you want for width or height but not both. For example, if you want an image to be 640 pixel wide, type 640 in the width box. The program will adjust the height accordingly.
To save the file:
1. Select File->Save As from the menu. This brings up the "Save Picture As" dialog.
2.Select "JPG - JPEG Files" from the "Save as type" drop-down.It looks like the default type is BMP and this is probably what is causing you grief.
3. With JPG as the "Save as type" you should see a "JPEG/GIF save options" dialog. Use the "Save quality" slider to adjust the file size. IrfanView doesn't show the file size in that dialog so you may need to save the file, check its size, adjust the quality and re-save to get the desired file size. You will probably need to adjust the quality setting differently for each image. A simple image without a lot of fine detail can be saved at a higher quality setting than a complex, detailed image.
Discussion
4 repliesIf there is anyone out there who can educate me on scanned slides and resizing in Irfanview. I get my slides scanned at 400dpi and put on CDs. I figured out how to resize when looking at the slide on my computer, but I've noticed that when I put them in emails, etc as attachments that the size I'm seeing on my computer is not the actual size. For example I download a file and resize it at 300dpi and 920 on the longest side and it looks about 8x12 on my computer, but when received by others is 1.5x2.5 inches. Also, how can I get a 125kb file at about 680x420 (approx.) using these scans...the files always seem too big according to the file size (MB and KB)on my screen...so I resize them to lower the kb size and I think I'm ending up with tiny photos when sent online. Is this not possible? There's something I'm missing or don't get. Hope someone can help. P.S. I'm very low tech, and don't have photoshop or any graphic capabilities. Just the CD scans and viewing capability with the Irfanview. Also, when received by someone else, if they have photoshop, can they resize on their end?
Thanks in advance,
Cynthia Spence
For the resizing, I have to admit that I am not familar with the program, so I am going to take some guesses as to what you can do. If it has an option to resize (which I have know idea if it does), and you want to resize for web use, computer use, or e-mail browsing, use that. Resize as follows:
dpi: 72
longest side (which ever that is) 680.
Photoshop will make you do the dpi selection first, then the longest size. If you reverse the order, the file gets really teeny. It is a quirk, but you get use to it.
There may be an option to constrain proportions. Basically, you don't want to start with a file that is, say 1200 by 1800, resize one side to 680, and then not have the other side resize, so you get something like a 680x1800 image.
For saving and file size:
Look for an option called save as, then look for a jpeg saving option. Ideally, you'll get a couple of saving option, small, medium large, or maybe a corresponding number. PS lets you pick numbers between 1 (small file size) to 12 (huge file size). You'll need to play with that to get the sizes to a number you are happy with. Lots of details will always give a larger file that one with little detail, so using a blanket resizing of say, medium, will give different results.
With regards to the different sizes on screen from what you see and what the viewer sees, it sounds like that might be partly the software being used to view the files. Assuming that the file is the same number of pixels on each side, and it is viewed at 100% (or any other consistent percentage), it should appear at the same size on different monitors. I have, off of the top of my head, 5 ways of viewing images on my home computer, and they all come up with different sizes when viewed on the screen. Once they are brought up to 100%m they are the same, though.
I have know idea if any of that helps, especially since I am not familar with the software.
The scanner resolution (dpi) determines how much information the scanner will extract from the film and how many pixels will be in the resulting image. If you need to resize the file for screen display only, then the output dpi doesn't matter. The only thing that does is the pixel size.
I'm also not familiar with Irfan but look for a function that will allow you to set the image dimensions in pixels.
Guy
Now let’s consider the images you have that are 920 pixels wide. If you set these to 300 dpi images, their actual size will be just over 3 inches wide. Again, what you see is dependent on the software you are using and perhaps how the preferences are set to display. If your images will be mostly viewed on a computer screen, such as in an email program, try setting the image resolution to 150 dpi, or even 100 dpi. The image will look just about the same on screen, but larger.
Resizing is fairly easy with most image processers. And although you can actually make a picture larger (more actual pixels, not just changing the dpi) than it was, the results are often not too good. Changing the dpi settings only affects the display size, though.
Russ
I have IrfanView installed on a USB key and I just took a quick look at it. I think I see what you need to do.
To resize:
1. Select Image->Resize/Resample from the menu. This brings up the "Resize/Resample image" dialog.
2. Make sure "Preserve aspect ratio" is checked.
3. In the "Set new size" portion of the dialog type in the dimensions you want for width or height but not both. For example, if you want an image to be 640 pixel wide, type 640 in the width box. The program will adjust the height accordingly.
To save the file:
1. Select File->Save As from the menu. This brings up the "Save Picture As" dialog.
2.Select "JPG - JPEG Files" from the "Save as type" drop-down.It looks like the default type is BMP and this is probably what is causing you grief.
3. With JPG as the "Save as type" you should see a "JPEG/GIF save options" dialog. Use the "Save quality" slider to adjust the file size. IrfanView doesn't show the file size in that dialog so you may need to save the file, check its size, adjust the quality and re-save to get the desired file size. You will probably need to adjust the quality setting differently for each image. A simple image without a lot of fine detail can be saved at a higher quality setting than a complex, detailed image.
Hope that helps.
Cheers,