Can someone explain this? " Image Saving issue"

CaptFinn

I use photoimapct by Ulead. Ulead sold out to Corel along time ago so PI isnt available anymore. But its all I know and use. Maybe someone with a
background in digital art graphic design can explain this image.

I saved 5 different images of a circle with different color schemes. And I saved them all same dimension and same file format. Didnt change any settings. Only the color scheme before saving as PNG.

Whats the math behind this. It seems to me the colors you use in your app are just as important as the image size and format.

tenrdrmer

I've wondered about this before too. How different images with the same dimension sizes can have different file sizes?

old_kipper

Images are stored with compression and there are a number of methods for compressing, but most rely on the fact of finding groups or rows of pixels that are the same or so similar that if made the same as those close by that they can be described in the image description in the file as an area of the same colour rather than different colour references for each pixel. Often in lossless compression the image is read horizontally and stored as something like 'all the next 300 pixels are the same colour'. So as you can see in your image where there is a gradient that changes along the line of a horizontal line more information has to be stored and the file size is therefore larger.

In lossy compression like jpeg you may have noticed squares becoming apparent as the file is more compressed. This is the algorithm averaging areas of colour out but as you push the size down it becomes more and more visible.

I hope that helps. Kipper

CaptFinn

The Rainbow and the brown are tha same size

old_kipper

Jeffnichols said:
The Rainbow and the brown are tha same size

That is because the image runs the same colour from the start of the line to the end. Only the description of the change of each row has to change therefore a very small size difference in the file.

SlickZero

Gradients, blurs, multiple colors, bleeding, all come in to play when it comes to file size on an image. Same thing with video, it's all about the colors, and how they transition into one another.

CaptFinn

so should I stay away from making images for GS with Gradients?

SlickZero

Not at all. The file sizes are really so minuscule, it doesn't matter. Your main worry will be with the scripting of things, and not using too many behaviors that will impede your game performance. As long as your image is optimized and the correct size, it should have no adverse affects on performance.