Mini Tutorial - Prepping an image for contest specs using IrfanView

[HappyCynic]

It's been mentioned several times that a tutorial would be helpful for those preparing images for the contests. This mini-tutorial covers changing the pixel size and file size of an image using IrfanView (http://www.irfanview.com/). I'm using the latest version - v4.25. It's a bit late for the latest contest, although if you need to resize, voting hasn't started yet so if you ask JeffR nicely, he might let you update it.

Note that for the contests, the rules typically state the image should be no longer than 800 pixels on its longest side and less than 200 KB.
What some people might not realize is that photos from digital cameras are typically saved with some extra information (the EXIF data) that can be removed. This data just stores the camera type and settings (including lens settings), date, and other info. This info can take up a sizable chunk of the 200 KB. (For me, it takes up about 35 KB.) So, you'll want to save the image without this data in order to squeeze out a bit more quality.

So, here are the steps:

1. Process the images from the camera (cropping, white balance adjustments, colour corrections, conversion to b&w, sharpness adjustments, etc.) and save it to a jpg. Do not reduce the size and make sure you save it at 100% quality. This allows you a "master image" to work with.

2. Start IrfanView and load the jpg image.

3. Select Resize/Resample from the Image menu.


4. A dialog should appear. Make sure the check box next to "Preserve aspect ratio" is checked. Under "Set new size", change the longest dimension to 800. The other dimension will automatically adjust. Click OK when done.


5. The image is now ready to save. I save the modified image in a new folder. Select Save As under the File menu.


6. At the bottom of the dialog that appears, select jpg format and make sure the "Show options dialog" check box is checked.


7. The options dialog should appear on screen and look something like the following:

These check box settings are what I use for my images.

8. Make sure the "Keep original EXIF data" check box is NOT checked.

9. Adjust the quality setting and save. Don't close IrfanView. Check the size of the file saved. If it is higher than 200 KB, go back to IrfanView and save it again using a slightly lower quality setting. Repeat the quality adjustments as needed until the saved image is below 200 KB.
Note that IrfanView works off of the original image loaded so if you save an image with a 90% quality setting, then go back and select save as with a 95% quality setting, the second image will be the originally loaded image at 95% quality, not the 90% quality image.

Hope this helps.

[JeffR]

1. Thanks for posting this!

I think every contest host should link this post in their submission thread. I certainly will if I get to host again.

[Sacred Fire]

2. Grazie!

This is very helpful. Thank you for taking the time to post this.

Now I won't have to wonder how I managed to make it happen 'last time'. :blush:

[Callalily]

3. Great tutorial.

Thanks, your hard work is much appreciated.

[Celebration]

4. An easy way for the Quality (only) Settings

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=280&topic_id=55672#55718

From a ConsAreLiars post

(this seems easier to me, just for the quality)

"That program offers much more, but resizing requires just one click on the "Image-resize/resample" menu and typing 800. And there's an "Undo" if one typed 80 or 880. Then it's simply a matter of choosing "Save for Web" and moving a slider to get the appropriate (under 200KB) size, or any other size wanted for any other purpose and putting the resulting file up on the web to make it accessible.

The main page is http://www.irfanview.com /
People will need to download the main Irfanview program and the Irfanview Plugins, install the main program and then the Plugins. The only downside is that is for Windows machines only."

I always resize the quality using the "Save for Web" feature (Infranview).

[HappyCynic]

10. Alternate Steps 5+ (Save for web)

That is easier. I prefer to use the "save as" rather than "save for web" personally. I personally like to see all the options - must be the computer geek in me. I can definitely understand how others may prefer using the "save for web" method, though. So, here are alternate steps for using the "save for web" option.

5. The image is now ready to save. I save the modified image in a new folder. Select Save For Web under the File menu.



6. A dialog should appear with the initial image on the left and the adjusted quality (optimized) image on the right. At the top of the dialog, just above the images are the file sizes. The save button is at the top left. Check the size of the optimized image. You can zoom in/out using the menus or the buttons between the images. As this tutorial only covers adjusting the image/file size, functionality that does not affect the file size will not be covered here.



7. At the bottom of the dialog are the image options including the image quality bar. If the optimized image is too large, adjust the quality setting until the image is under 200 KB. Note that if you click on the arrow buttons on either side of the image quality bar, the size will update immediately. If you grab the slider box and drag, the optimized image size updates only when you let go. You typically don't need to change the quality much so it's probably better to use the buttons. (If the image at 100% is about 250 KB, 98% is a good place to start. If the image is roughly 350 KB, 92% is probably a good place to start.)



8. When the optimized image size is under 200 KB, press the Save button.

9. Select the folder to save to and click on the Save button.

[Celebration]

5. One more thing

When posting contest entries, please hit the "preview" button before posting, and check the settings using "properties" (right click the picture).

Okay, now I can breathe. At one point I actually needed to be told that. Since we seem to have new entrants each month someone might need that.

[Sacred Fire]

8. now that is...

an example of Smartness!

[Mira]

6. Very excellent work. Thank you. I bookmarked it for the future. N/T

[alfredo]

7. Video tutorial for the Mac.

http://www.youtube.com/watch?v=yWqXD-Fvk0Y


Double click image icon and image will open in Preview. Go to tools in the menu bar. Select Adjust Size.

A dialoge will appear. Change the largest number to 800 if you are resizing for the contest. The other number will automatically change to the appropriate size, or you can just click on the field and it will change.

Hit Save As under the File Menu. You will see a quality slider and under that the file size. Adjust the slider until you reach 200 or as close as you can get.

Hit save and you are done.


Remember not to change the file name if you are replacing one online. The site will automatically detect a similar title and ask if you want to replace the old one. That will keep you from double posting.

[HappyCynic]

11. Thanks

Thanks for the Mac info. I don't have a Mac and my image processing tools are limited so I'm not able to provide much in way of alternate programs and/or alternate operating systems. This should be very helpful for those that are using Macs.

[alfredo]

14. Thanks. Preview has become a very good image processor. It's really simple too.

[HappyCynic]

16. Adding to journal

Thanks, alfredo. Adding this to my journal.


http://www.youtube.com/watch?v=yWqXD-Fvk0Y


Double click image icon and image will open in Preview. Go to tools in the menu bar. Select Adjust Size.

A dialoge will appear. Change the largest number to 800 if you are resizing for the contest. The other number will automatically change to the appropriate size, or you can just click on the field and it will change.

Hit Save As under the File Menu. You will see a quality slider and under that the file size. Adjust the slider until you reach 200 or as close as you can get.

Hit save and you are done.


Remember not to change the file name if you are replacing one online. The site will automatically detect a similar title and ask if you want to replace the old one. That will keep you from double posting.

[alfredo]

9. Add this thread to your journal.

[HappyCynic]

12. Thanks for the suggestion

I've now added this to my journal.

[alfredo]

13. That will give you easy access to the info. Also copy my Mac tutorial.

The video is quite good.

[ManiacJoe]

15. In step 4,

One might want to play with the checkbox for "apply sharpen". Most often images that get reduced in size need some final sharpening after the resize.

I step 7, while I do not normally recommend removing the EXIF data, in this case the goal is to reduce the file size.

[Juneboarder]

17. This is a wealth of information

Thank you for posting this... I appreciate you taking your time :)