CuteAlien wrote:Well, Irrlicht won't magically improve a bad quality image. But it also shouldn't display jpg worse than they are shown in other image tools (at least as long as they are POT).
well, it's like a TV screen, the closer you get to the screen the more you see the pixels and if you're close enough you can identify each color a pixel is build of, and if you go farther away the picture gets sharper (for your eyes/brain)...
so if you get closer to a node with bad quality texture you'll see the bad quality better than from a distance...
and it also depends on the node's size (of course), a large node is like you're close to a small node and vice versa...
I often like to compare jpg and mp3, because mp3 does something similar, but for sound...
mainly it removes details that (usually) no one can hear/recognise, so you wont hear a difference to the original, but there is a difference (quality loss) and depending on the encoding settings you get better quality but bigger files or bad quality and smaller files...
@CodyCer0: well, it's not that easy, but it goes in the right direction...
Wikipedia wrote:JPEG codec example
Although a JPEG file can be encoded in various ways, most commonly it is done with JFIF encoding. The encoding process consists of several steps:
1. The representation of the colors in the image is converted from RGB to YCbCr, consisting of one luma component (Y), representing brightness, and two chroma components, (Cb and Cr), representing color. This step is sometimes skipped.
2. The resolution of the chroma data is reduced, usually by a factor of 2. This reflects the fact that the eye is less sensitive to fine color details than to fine brightness details.
3. The image is split into blocks of 8×8 pixels, and for each block, each of the Y, Cb, and Cr data undergoes a discrete cosine transform (DCT). A DCT is similar to a Fourier transform in the sense that it produces a kind of spatial frequency spectrum.
4. The amplitudes of the frequency components are quantized. Human vision is much more sensitive to small variations in color or brightness over large areas than to the strength of high-frequency brightness variations. Therefore, the magnitudes of the high-frequency components are stored with a lower accuracy than the low-frequency components. The quality setting of the encoder (for example 50 or 95 on a scale of 0–100 in the Independent JPEG Group's library[4]) affects to what extent the resolution of each frequency component is reduced. If an excessively low quality setting is used, the high-frequency components are discarded altogether.
5. The resulting data for all 8×8 blocks is further compressed with a loss-less algorithm, a variant of Huffman encoding.
The decoding process reverses these steps. In the remainder of this section, the encoding and decoding processes are described in more detail.
so in my opinion bmp is the best format if you want good quality, presupposed you don't need an alpha channel !!!
the file size doesn't matter here, because you can zip the files...
and remember that the same image uses the same RAM, regardless if it's a jpg or bmp, it only makes a difference on disc space...
but I also must admit that I'm using jpg, too (most of the time)...