Reducing file size

[LindyJo]

I have just been trying to post a picture in the competition but it is saying that the file size is too big. Does anyone know how I go about reducing this?
Thanks,

LindyJo

[hollis_f]

Originally Posted by LindyJo

I have just been trying to post a picture in the competition but it is saying that the file size is too big. Does anyone know how I go about reducing this?
Thanks,

LindyJo

There are two ways one can reduce the file size. Using a combination of both is often necessary. I'll describe the methods - the actual processes depend on what image-editing software you use.

Firstly one can reduce the actual number of pixels in your image. This is done using the 'Resize' command. For Gallery images your best option is to reduce the image so that it is somewhere between 800 and 1000 pixels in the longest dimension. Make sure you keep the aspect ratio the same size. You can also use the 'Crop' command to cut out a portion of your image. Open up your image-editing package and look in the help for 'Crop' and 'Resize' - then play with these options (using a copy of the image you want to manipulate).

The other option is to increase the amount of compression used. This can greatly reduce file size, but can result in image degradation if too much compression is used. The amount of compression is normally an option when you use the 'Save As...' command. Again, search the help for 'compression'.

If you let us know what package you've got (often something like Photoshop Elements is included with a camera) then somebody will be able to give detailed instructions.

[LindyJo]

I am currently using Corel Paint Shop Pro at the moment as I haven't managed to get my hands on PhotoShop yet. I thought it would be something to do with reducing the pixels but didn't want to lose any quality in the image. I have reduced it by half now so will attempt to post it again, fingers crossed...

[yelvertoft]

Hi LindyJo,

I used PSP for many years but switched a year ago. After you have resized your image, from memory I think if you do a "save as" and then click on the "options" box you will get a sliding scale for amount of compression to use. This will affect the file size.

For viewing at the kind of file sizes commonly posted on WPF you aren't going to gain much by pushing the slider up more than about 75% of the way towards the right. You will notice very little difference once you get to more than 65% unless your image is particularly complex and patterned.

Duncan

[robski]

On a general note if you shoot at a high ISO setting the high levels of noise in the image will give poor data compression. Noise reduction programs such as Neat image and Picture Cooler can be very effective in reducing image noise and thereby improve the image compression ratio.

[Don Hoey]

Originally Posted by yelvertoft

Hi LindyJo,

I used PSP for many years but switched a year ago. After you have resized your image, from memory I think if you do a "save as" and then click on the "options" box you will get a sliding scale for amount of compression to use. This will affect the file size.

For viewing at the kind of file sizes commonly posted on WPF you aren't going to gain much by pushing the slider up more than about 75% of the way towards the right. You will notice very little difference once you get to more than 65% unless your image is particularly complex and patterned.

Duncan

Hi LindyJo,

I use Paint Shop Pro and the method Duncan has described is the way to go.

I have versions 7 and 8, and if you want, I can do a series of screen captures and text description of the route I take. The dialogue boxes are a bit different so if you are on either of these versions I can do the screen captures in that version.

Don

[LindyJo]

Thanks everyone for your replies, I think I have figured it out as I have now managed to download 2 pictures onto the site. I only got my new camera last month so I am picking up new stuff every day.

As we are still getting a lot of images too small to do justice to the subject, may I offer a re-cap?

Suggest posting 1024x768, though even if you post 1280x960 the software will enlarge it into its own window for those with a decent screen. I would not worry too much about copyright issues, though I suggest and offer a 'please don't copy me' stamp that can be placed inconspicuously in an area difficult to clone back out.

I am a mac user and rarely use Photoshop (Elements), but the basic technique is similar in whatever software

(1) crop out anything not needed
(1a) at this stage use 'unsharp' (if needed, ie sharpen, but no more than essential) and possibly adjust 'brightness/contrast', because compression stage and site software dull the colour range
(2) resize the pic to 1024x768 (500x768 for portrait); suggest Lanczos 3 algorithm if available (use answers.com to understand algoriths more)
(3) 'save as' and adjust the % quality to bring below 400kb. You will find some pics need less compression at this stage than others, depends on the variety of colour and tone in the pic. Also greater compression sometimes gives greater clarity, which can be seen in preview window
(4) 'save as' so as to keep original uncompressed for printing and maybe improved post-processing when your technique has improved - 1st class lessons given in Critique Forum!