Reducing a JPEG

[tyler4402]

Hi all, I want to put a photo into a competition, and to enter the rules say that I need to reduce a jpeg photo to 300K whatever that is?
When I look at my photo properties they are usually given between 1.53 Mb and 3.05Mb so what I would like to know is how to change them from Mb to K
Usually for fast transfer by email I reduce them by 30% which works Ok using the photo program I use which is Faststone Image Viewer which seems to work very well, but when I click onto the FastStone link for help nothing happens which makes me wonder if they are still in business.

Regards Robert.

 

[Woodsman]

I use Fastone as a quck viewer as well. To reduce the size you need to alter the compression rato and/or the image size. Open the image in your viewer and then move the mouse the left hand side and then select resize/resample to lower the file size in pexels and then do a save as

The easiest way to do it is from the file list. Highlight your file and then from the menu at the top select TOOLS, from thr drop down select "Batch convert selected images"

When the diaglog opens the file name will be in the box on the right. Below this box you will see settings, click this to adjust the compression ration, lower numbers give you a lower quality output but a smaller file size. Use this in conjuction with the botton for Advanced Options. Here you can change the size of the file in pixels. PLay with both to give you a combination of a smaller picture but good quality for example under adanced chose a standard size such as 1024x768 and then under settings choose a compression ratio of 8 and see how close the final saved file is to your 300K. If its still to large reduce the compression ratio to 7

Remember to copy to a test directory first or use a different file name. You do not want to replace your original with a lower res copy

 

[ph0enix]

In binary computing, a bit (b) is the smallest unit of data. The next one up (besides the nibble) is byte (B) - it usually consists of 8 bits. 1,024 bytes (2^10) is a kilobyte. That's what the 300K or 300KB means. A megabyte or M/MB is equal to 1,024 kilobytes (or 1,048,576 bytes).

Windows PCs come with an app called Paint. You can find it in the Accessories menu (or search apps for it in Windows 8). It will allow you to resize the image. Be sure to make a copy of the original file or use the "Save As" option and give the file a new name. If you just "Save" after resizing, the original file will be overwritten.

 

[The_Traveler]

you need to know two things.

What dimensions they want in pixels and what filesize they want in bytes.
The eventual size of the file depends on the dimensions in pixels and the amount of compression that is done on the resized file.

Unless you have a VERY highly detailed image, for file dimensions of 1024 x 768 (a not uncommon size for contest submission), compression down to 60% will give you a very decent quality image at about 300 k

Here is a random image that is 1024 x 768 in pixel dimensions, compressed when saving for web to 60% quality (high medium) and it is 239 k in size
(this is totally unedited except saving from opened raw file to jpg so it has not been resharpened.)

 

[tyler4402]

Hi Guys, thanks for the help and info, I have just come back to the site to check as I though that I would get email alerts when someone answered? anyway I am off for 4 days in the morning so when I get back I will have a go following your instructions, and then come back to let you know how I've got on, again my thanks for your response and help, regards Robert.