Asset image size questions

[Griogre]

IrfanView is a free image manipulation program that has built in batch processing. It's super good for resizing and de-rezing.

Just to follow up on Moon Wizards comment on webp - webp are awesome when it comes to file compression - saving tons of space on your fixed drives/SSDs. However, the real image size issues in FGU revolve around the size of an image in *memory*. There is no image compression in FGU memory so an image that doesn't take up much file space can take up a lot more memory space. Just to give a small example the Black Dragon Token below is only 20K as a file but is 264K in memory.

This has little effect on things like tokens and portraits but it matters a lot with map images. It's easy to have a map image that is only a few megs that is 10 times larger in memory. Its the 10 times larger memory size that is actually transferred and updated.

[pindercarl]

IrfanView is a free image manipulation program that has built in batch processing. It's super good for resizing and de-rezing.

Just to follow up on Moon Wizards comment on webp - webp are awesome when it comes to file compression - saving tons of space on your fixed drives/SSDs. However, the real image size issues in FGU revolve around the size of an image in *memory*. There is no image compression in FGU memory so an image that doesn't take up much file space can take up a lot more memory space. Just to give a small example the Black Dragon Token below is only 20K as a file but is 264K in memory.

This has little effect on things like tokens and portraits but it matters a lot with map images. It's easy to have a map image that is only a few megs that is 10 times larger in memory. Its the 10 times larger memory size that is actually transferred and updated.

The size on disk effects the amount of network traffic as the files must be sent to each client. The smaller the file, the less network traffic.

When an image is displayed, Fantasy Grounds will open the image, push the image to the GPU, and then discard the image data from memory. Images take up memory on the GPU, not in main memory. Images greater then 100x100 pixels are compressed before being sent to the GPU. Images without an alpha channel (transparency) are compressed 8:1. Images with an alpha channel are compressed 4:1.

For example, a 256x256 pixel uncompressed image with an alpha channel is 256KB. With Webp compression at 75%, it might be around 24KB on disk. On the GPU the image will use 64KB. Without an alpha channel, it would be 32KB. A 2048x2048 image (like you might use for a map) is 16MB uncompressed, or 4MB with transparency and 2MB without transparency. The memory usage on the GPU will be of most concern to users with an integrated GPU, like an older Intel based Mac mini or many laptops, as these share the main memory. You may have a dedicated GPU with 8 GB of memory, but your players may have lower spec computers.

[Griogre]

@pindercarl, thank you for the information.