Raspberry Pi A, Руководство пользователя, Страница: 291 / 314

A P P E N D I X B
R A S P B E R R Y P I C A M E R A M O D U L E Q U I C K R E F E R E N C E
275
❍
-w or --width (Width)— Specifies the width, or horizontal resolution, of the captured
image or video. This should be set to the desired width in pixels; for example, a Full HD
capture would require a width value of 1920. The minimum value is 64; the maximum
depends on whether a still image or a video is being captured.
Raspistill Options
Designed to capture still images,
raspistill
has some specific options that do not apply
to
raspivid
. These options are listed below.
❍
-e or --encoding (Encoding Format)— Sets the format of the output image. This
does not affect the file extension of the output file, which must be changed manually
using the
--
output option. Possible values for this option are
jpg
,
bmp
,
gif
,
png
.
❍
-q or --quality (JPEG Quality)— Sets the compression level of the saved JPEG, and has
no effect when using any other encoding format. The lower the value, the smaller the
final image file; a value of 100 will provide the best possible quality, while a value of 0 will
provide the smallest file size. A value of 90 is a good trade-off between size and quality.
❍
-r or --raw (Save Bayer Data)— Saves the output of the camera’s Bayer colour filter
as metadata in the JPEG image, and has no effect when using any other encoding for-
mat. This extra data, the output of the camera’s sensor without interpolation, can be
used in image editing applications to reconstruct a higher quality or more detailed
image, but is not normally required.
❍
-th or -–thumb (Thumbnail Settings)— Sets the size and quality of the thumbnail
saved with JPEG images, and has no effect when used with any other encoding format.
The value should be given as X:Y:Q, where X is the width, Y the height and Q the JPEG
quality from 0 to 100 of the thumbnail.
❍
-tl or --timelapse (Timelapse Mode)—
Puts
raspistill
into timelapse mode,
where images will be captured at a set interval. Most useful when using
raspistill
with a script or third-party application by setting the Output file to the standard out-
put with a hyphen (
-
) character; when used with a filename in the
--output
option,
the file will be overwritten every time a new image is captured. The value for this option
should be the delay between captures in milliseconds.
❍
-x or --exif (EXIF Tag)— Allows custom Exchangable Image File Format (EXIF) tags
to be written to a JPEG image, and has no effect when used with any other encoding
formats. Tags should be formatted as ‘key=value’ with one possible example being set-
ting the name of the photographer using
-x ‘Author=Gareth Halfacree’
.