Constructor
VipsImagejpegload
Declaration [src]
int
vips_jpegload (
const char* filename,
VipsImage** out,
...
)
Description [src]
Read a JPEG file into a VIPS image. It can read most 8-bit JPEG images, including CMYK and YCbCr.
shrink means shrink by this integer factor during load. Possible values
are 1, 2, 4 and 8. Shrinking during read is very much faster than
decompressing the whole image and then shrinking later.
Use fail_on to set the type of error that will cause load to fail. By
default, loaders are permissive, that is, VIPS_FAIL_ON_NONE.
Setting autorotate to TRUE will make the loader interpret the
orientation tag and automatically rotate the image appropriately during load.
If autorotate is FALSE, the metadata field VIPS_META_ORIENTATION is set
to the value of the orientation tag. Applications may read and interpret
this field
as they wish later in processing. See vips_autorot(). Save
operations will use VIPS_META_ORIENTATION, if present, to set the
orientation of output images.
Example:
vips_jpegload("fred.jpg", &out,
"shrink", 8,
"fail_on", VIPS_FAIL_ON_TRUNCATED,
NULL);
Any embedded ICC profiles are ignored: you always just get the RGB from
the file. Instead, the embedded profile will be attached to the image as
VIPS_META_ICC_NAME. You need to use something like
vips_icc_import() to get CIE values from the file.
EXIF metadata is attached as VIPS_META_EXIF_NAME, IPTC as
VIPS_META_IPTC_NAME, and XMP as VIPS_META_XMP_NAME.
The int metadata item “jpeg-multiscan” is set to the result of
jpeg_has_multiple_scans(). Interlaced jpeg images need a large amount of
memory to load, so this field gives callers a chance to handle these
images differently.
The string-valued field “jpeg-chroma-subsample” gives the chroma subsample in standard notation. 4:4:4 means no subsample, 4:2:0 means YCbCr with Cb and Cr subsampled horizontally and vertically, 4:4:4:4 means a CMYK image with no subsampling.
The EXIF thumbnail, if present, is attached to the image as
“jpeg-thumbnail-data”. See vips_image_get_blob().
Optional arguments
shrink:gint, shrink by this much on loadfail_on:VipsFailOn, types of read error to fail onautorotate:gboolean, use exif Orientation tag to rotate the image during load
See also
This constructor is not directly available to language bindings.
Parameters
filename-
Type:
const char*File to load.
The data is owned by the caller of the function. The value is a NUL terminated UTF-8 string. out-
Type:
VipsImageDecompressed image.
The argument will be set by the function. The caller of the function takes ownership of the returned data, and is responsible for freeing it. ...-
Type:
NULL-terminated list of optional named arguments.