On Fri, 20 Apr 2001, Damien Seguy wrote:
>Hi,
>
>Lately, I used getimageisize on a JPEG picture, and I got extra index in the
>returned array.
>
>> [bits] => 8
>> [channels] => 3
>> index 0 through 3 are documented but not "bits" and "channels".
>
>I talked with Wez, and here is his conclusion :
>
>'channels' is the number of channels;
>most likely 3 for RGB images, 4 for CMYK images.
>
>'bits' is the number of bits of information per channel.
>
>So bits = 8 and channels = 3 implies that you have an RGB image, with 8 bits
>per pixel; 8 * 3 = 24 bits per pixel (or true colour) image.
>
>This sounds sensible, but can anyone with greater experience validate this?
>If anyone disagree, I'll add it in the docs.
>
According to the image.c the bits / channels are set only for JPEGs.
--Jani
