Image formats

posted on June 30th, 2010, 2:56 am

Hi guys..... I am curious, what is the best 'reduced-memory-use' image format that does not loose much of the image quality? Because I have these large .tiff files that are a real killer on space (ranging from a few megabytes to at least 20 megabytes, I also have a few that are about 200 megabytes!) and I want to convert them into a common image format so I could have them as desktops. But, as the quality addict I am. I don't want to loose any of its quality. Is there a format where I get the best of both worlds?

posted on June 30th, 2010, 3:05 am

I like PNG it has good quality and is a widely supported format.

posted on June 30th, 2010, 3:36 am

PNG also supports transparency, also called alpha channel.

JPG is also a good format for keeping size down, though it doesn't use an alpha channel. Most image editing programs also allow for exporting JPGs at 100% quality but others such as MS Paint tend to reduce quality and, by extension, file size in JPGs.

posted on June 30th, 2010, 3:46 am

PNGs are good; the only catch with alpha channels is that alphas will not necessarily be utilized when simply porting from one format to another. JPGs with little or lossless compression are pretty good if you don't mind a slight amount of quality loss, it probably won't be noticeable though; JPGs could still be more than 1 MB if the images were particularly large to begin with, that is if they have a high resolution.

If you've got something like Photoshop you might want to consider using that program's native format. While I don't know the quality-to-size relation of say PSD files I would imagine that it's not terrible.

posted on June 30th, 2010, 4:08 am

He wants to use the images for desktops, though, so he can't use a PSD.

posted on June 30th, 2010, 4:31 am

Oops, missed that, sorry. In that case PNG is probably best.

posted on June 30th, 2010, 5:38 am

well i know .tif files can be mega small especially if you use photoshop compression options on them (smallest format i've found that keeps quality, layers and alphas but i do not know if they can be set as desktop images (i know they cant in XP but mayby vista or win 7 they can but i do not know

posted on June 30th, 2010, 6:35 pm

Yeah PNG is probably best.

[Tyler]

posted on June 30th, 2010, 6:43 pm

Last edited by Tyler on June 30th, 2010, 6:45 pm, edited 1 time in total.

I prefer JPG images. Mainly because they are a lot smaller than PNG.

posted on July 1st, 2010, 6:04 am

only issue with jpeg is that it can loose quality were png and bmp do not tend to

posted on July 1st, 2010, 6:28 am

I'd be really anal and say:

Jpeg for "Screenshots"
PNG for "AWESOME SCREENSHOTS"

In terms of space saving jpegs will ram into the tinest of spaces but they do lose a little quality and have the best bang for buck in terms of file sizes. PNG's give the value when it comes to lossless quality, from what I've used.

posted on July 1st, 2010, 11:30 am

i find for uploading to the forums, png is way too large. u can only fit a couple screenies per post.

i have compared fo screenies in jpg and png format, and the jpg doesnt lose too much quality. this is the jpg made by using paint to convert from fo native png to jpg.

posted on July 1st, 2010, 2:07 pm

I personally use Gimp for my graphics editor. When you export a JPG in my edition of Gimp (which is ancient) you have a quality loss slider so you can set it to keep 100% quality.

posted on July 1st, 2010, 2:23 pm

The main reason i like png is because of the quality and the alpha transparency. There is also tools to make your png a animation.

posted on July 2nd, 2010, 1:16 pm

i've done a test.

the purpose was to see if jpg or png was better for fo sreenies.

the result is that converting the native png screenshot to jpg doesnt lose quality.

i used this batch processor: http://www.etrusoft.com/graphic-convert ... verter.exe

set its quality to 100% and u will achieve a significant drop in file size without a loss of quality.

attached is an image comparing the two formats.

two sources were used, the top source is the native png format given by fo. the bottom source was the same image but converted to jpg using the program above.

i pasted them into paint and saved as png. the top source wouldnt be affected by this as it was already a png image, if the bottom source (the jpg) was really of lower quality then saving as png wouldnt improve the quality (u cant recover quality lost to compression) and the bottom would look worse than the top. but as u can see the bottom and top look the same (at least to me they do)

Attachments