Function

Vipsjpegload

Declaration [src]

int
vips_jpegload (
  const char* filename,
  VipsImage** out,
  ...
)

Description [src]

Optional arguments:

shrink: %gint, shrink by this much on load
fail_on: VipsFailOn, types of read error to fail on
autorotate: %gboolean, rotate image upright during load

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", &amp;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().

See also: vips_jpegload_buffer(), vips_image_new_from_file(), vips_autorot().

This function is not directly available to language bindings

Parameters

`filename`	`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`	`VipsImage`
	Decompressed image.
	The argument will be set by the function.
	The called function takes ownership of the data, and is responsible for freeing it.
`...`
	`NULL`-terminated list of optional named arguments.

Return value

Returns:	`int`
	0 on success, -1 on error.