How the samples in the GeoTIFF files (also
known as bands), are mapped to the color channels of an RGB(A) image.
Must be an array of either 1, 3 or 4 elements. Each element is the index of a sample in the
source file. For example, to map the samples 0, 3, and 2 to the R, G, B colors, you can use
[0, 3, 2].
1 element means the resulting image will be a grayscale image
3 elements means the resulting image will be a RGB image
4 elements means the resulting image will be a RGB image with an alpha channel.
Note
If the channels is undefined, then they will be selected automatically with the
following rules: if the image has 3 or more samples, the first 3 samples will be used,
(i.e [0, 1, 2]). Otherwise, only the first sample will be used (i.e [0]). In any case,
no transparency channel will be selected automatically, as there is no way to determine
if a specific sample represents transparency.
Examples
I have a color image, but I only want to see the blue channel (sample = 1): [1]
I have a grayscale image, with only 1 sample: [0]
I have a grayscale image with a transparency channel at index 1: [0, 0, 0, 1]
I have a color image without a transparency channel: [0, 1, 2]
I have a color image with a transparency channel at index 3: [0, 1, 2, 3]
I have a color image with transparency at index 3, but I only want to see the blue channel:
[1, 1, 1, 3]
I have a color image but in the B, G, R order: [2, 1, 0]
How the samples in the GeoTIFF files (also known as bands), are mapped to the color channels of an RGB(A) image.
Must be an array of either 1, 3 or 4 elements. Each element is the index of a sample in the source file. For example, to map the samples 0, 3, and 2 to the R, G, B colors, you can use
[0, 3, 2].If the channels is
undefined, then they will be selected automatically with the following rules: if the image has 3 or more samples, the first 3 samples will be used, (i.e[0, 1, 2]). Otherwise, only the first sample will be used (i.e[0]). In any case, no transparency channel will be selected automatically, as there is no way to determine if a specific sample represents transparency.Examples
[1][0][0, 0, 0, 1][0, 1, 2][0, 1, 2, 3][1, 1, 1, 3][2, 1, 0]