Question about image size

[Darth Bane]

Howdy folks!
Just a quick question about image sizes.
After rendering my images in Daz they come out anywhere between 2 - 5mb.
Looking at most of the games I play, the image size is usually under 1mb in size, even a game with beautiful renders like 'The Secret' has jpg sizes at 1920x1080 resolution hitting the 400kb mark give or take.
Obviously there's a way of bringing down the size without significantly losing quality.
Any tips would be greatly appreciated!

 

[W22N]

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[Darth Bane]

Cheers mate! I appreciate it.

 

[Palanto]

I'd recommend rendering in png (full quality) and then using web'py on them to reduce the size jpgs are already compressed images with lower quality, so jpeg -> webp reduces the quality a bit more, but using png -> webp is kinda like rendering it in jpg but with smaller image sizes

 

[Rich]

There are a variety of different tools to reduce the size of JPG's - all involve size/quality tradeoffs.

As Palanto says, you might want to consider rendering to PNG, which is lossless, so that you have the highest quality "original," and then do a conversion to your game size to a different file. Not that the JPG's that DS puts out are bad - just don't throw away the original.

Some people really like the WEBP image format - my own experience is that it isn't hugely better than a carefully done JPG, but this is one of those "eye of the beholder" things, since you're evaluating image "quality," which is subjective.

If you're comfortable with command line tools, ImageMagick, provides a wide variety of conversions with tuneable quality. It can be used to "batch convert" a big bunch of files. Otherwise, Photoshop or GIMP will also let you save a JPG with varying degrees of compression.

 

[Palanto]

There are a variety of different tools to reduce the size of JPG's - all involve size/quality tradeoffs.

As Palanto says, you might want to consider rendering to PNG, which is lossless, so that you have the highest quality "original," and then do a conversion to your game size to a different file. Not that the JPG's that DS puts out are bad - just don't throw away the original.

Some people really like the WEBP image format - my own experience is that it isn't hugely better than a carefully done JPG, but this is one of those "eye of the beholder" things, since you're evaluating image "quality," which is subjective.

If you're comfortable with command line tools, ImageMagick, provides a wide variety of conversions with tuneable quality. It can be used to "batch convert" a big bunch of files. Otherwise, Photoshop or GIMP will also let you save a JPG with varying degrees of compression.

Well for me it's not only the quality/size that's better with webp but also the fact that webp does support transparency which jpeg doesn't.

 

[Rich]

Oh, of course - if you have an image that needs transparency, then you absolutely can't use JPG. At that point, it's PNG or WEBP, and WEBP is reported to usually do better compression-wise than PNG. (I say "reported" only because I haven't used WEBP as much as PNG for that, and these things are frequently dependent on the exact image being used. I'm not trying to put down WEBP - I just don't have sufficient experience with it to be comfortable making general pronouncements)

The flip side is that not every engine supports WEBP. Ren'py does, but some others don't. PNG is pretty universal.

So, "your mileage may vary."

 

[Palanto]

Oh, of course - if you have an image that needs transparency, then you absolutely can't use JPG. At that point, it's PNG or WEBP, and WEBP is reported to usually do better compression-wise than PNG. (I say "reported" only because I haven't used WEBP as much as PNG for that, and these things are frequently dependent on the exact image being used. I'm not trying to put down WEBP - I just don't have sufficient experience with it to be comfortable making general pronouncements)

The flip side is that not every engine supports WEBP. Ren'py does, but some others don't. PNG is pretty universal.

So, "your mileage may vary."

Also very true

But webp will be something to check out for the future since more and more engines, programs and so on are starting to use it. I'm still favoring .png but in my opinion webp > jpg

 

[anne O'nymous]

As Palanto says, you might want to consider rendering to PNG, which is lossless, so that you have the highest quality "original," and then do a conversion to your game size to a different file.
[...]
If you're comfortable with command line tools, ImageMagick, provides a wide variety of conversions with tuneable quality. It can be used to "batch convert" a big bunch of files.

The problem with conversions, is that the result will partly depend of the complexity of the scene. For come you can go 50% without problems, and for other going under the 10% create a real mess. So, if quality is what matter the most, what can be done is :

1. Render the scenes in PNG ;
2. Using ImageMagick to convert them in different quality while you do something else ;
3. For each scene, check what conversion achieve the best result and keep this one.

And anyway always (if possible) use ImageMagick for you image manipulations. It will be really time saving since it can be done while you sleep, while you are shopping, or even on the old (but not too much) computer you kept in the basement because, "who know one day it can be used again for something".