i4memory.com

08-09-2008 until 31-12-2009

I notice folks posting very large screenies including their whole desktop in background. It's alot easier to reduce and crop to only the area of a screen capture you want to show.

I thought i'd show you how much of a reduction you can get in size of the final screen shot.

Download www.irfanview.com and plugins...

prnt-scr -> open irfanview -> ctrl-v to paste image -> use mouse to highlight only area you want to show -> ctrl-Y to crop that area -> ctrl-R to resize it to 450-800pixels for forums -> save as -> jpeg -> options set at 65-75% quality

I used 65% jpeg quality on all below screen shots.

Full Desktop:
* prnt scr -> paste into irfanview -> jpeg 65% quality -> save as = 191kb

* print scr -> paste into irfanview -> jpeg 65% quality -> cropped to only info needed INCLUDES taskbar/clock -> save as = 182kb

* print scr -> paste into irfanview -> jpeg 65% quality -> cropped to only info needed crop away taskbar/clock -> save as = 160kb

* print scr -> paste into irfanview -> jpeg 65% quality -> cropped to only info needed crop away taskbar/clock -> resized smaller to legible font size (CTRL+R) -> save as = 108kb

3x CPUZ screenies + A64Tweaker:

* prnt scr -> paste into irfanview -> jpeg 65% quality -> save as = 124kb

* prnt scr -> paste into irfanview -> jpeg 65% quality -> cropped to only info needed showing -> save as = 111kb

* prnt scr -> paste into irfanview -> jpeg 65% quality -> cropped to only info needed showing -> resized (CTRL+R) -> save as = 72kb

For resizing (CTRL+R) ensure preserve aspect ratio is checked:

Additional Tips:
1. You can also batch resize folders of pictures all at once. Read Irfanview help file to find out how

2. If you save a screenshot which is unedited, without resizing as PNG file, you will get a smaller size than any JPEG compressed quality picture. However, if you resize a screenshot then save as PNG file it will result in a size larger than JPEG compressed quality picture. For example below picture thumbnail (44.79KB) is resized, cropped JPEG 60% quality which links to an non-resized original screen capture saved as PNG (66.39KB)

Update: September 21, 2006
Discovered you can save a further 40-50% reduction in screenshot size if you use Irfanview to convert to greyscale BEFORE you save an non-resized screen capture to PNG format with PNGOUT enabled at compression level 9.

These screenshots with PNG format at compression level 9 were around 36-60KB in size but now check out the image sizes!

Updated: March 15, 2007
More optimisation tweaks for smaller screen capture file sizes from SLI_dog

Originally Posted by SLi_dog

This is a how to on creating small file size screen captures using irfanview which is a truely great app thats absolutely free

First up you'll want to grab your self a copy of Irfanview and the plug in pack too.

www.irfanview.com

I've found that the smallest size screen captures are almost always in .png format. Irfanview has a great plugin called "png out" which really helps reduce file size even further.

Here are some examples. The following pictures are of the full desktop captured using the "CTRL+PrtScn" keys.

The first is just a normal save with irfanview in png using compression value 9. Notice that the image quality is as good as you'd see it on the screen.

File size = 122kb

This is the exact same save in .jpg format with the default jpg compression value of 80%. Notice that the image quality has been lost from that of the normal desktop. The file size has gotten bigger too

File size = 147kb

Now I'll just do a simple image crop by selecting the area I want to crop to by holding the left mouse button and dragging a box around the area then pressing "CTRL+Y" to crop. You can always resize the area after by dragging the edges of the crop selection box. This drops the file size to only 106kb, that's already a 1/6th size saving which means faster loading web pages for easier browsing.

File size = 106kb

At this stage I'll introduce the pngout plugin. The following is using the pngout default settings. Notice that the image quality is still as good as you'd get on the screen.

File size = 85kb

Now the real trick to reducing file size is to reduce the number of colours in the picture. You do get some decrease in picture quality but it's still very readable and the file size saving are huge. Here's how you do it.

Make sure you UNTICK the Use Floyd-Steinberg dithering or you'll end up with larger file sizes

The following are advanced settings for the pngout plugin that I've found give the best reduction most of the time. You want to change the "Compression level" to 9, change the "Block split threshold" to 4096, and click on the "Keep chunks" button and hit "Select none"

And if you put together the Reduce Colour Depth and Advanced png out settings you can get a file size reduction like this without compromising image quality too much.

File size = 32kb

I should point out that this will only work for simple screen captures, if you have normal photos or have a photgraphic windows backdrop then you may want to use .jpg

I think that having a 3/4th reduction is size is worth not having such a pretty backdrop while benchmarking

Don't just take my word for it, play around and see if you can find any better settings. If you do I'd be keen to know.

Update: September 8, 2008

Just an update, if you find irfanview PNGout method too slow and don't mind sacrificing some compression for speed, check out PNGoptimizer as well as other tools listed at http://forums.legitreviews.com/about16702.html.

Hint:
1. only crop don't resize screen captures when you save for PNG format
2. reduce colours to 256bit or 64bit before optimizing PNG/screen captures