C# 클래스 BitMiracle.LibJpeg.Classic.jpeg_decompress_struct

Aborts processing of a JPEG decompression operation.

Pre-calculate output image dimensions and related values for current decompression parameters.

This is allowed for possible use by application. Hence it mustn't do anything that can't be done twice. Also note that it may be called before the master module is initialized!

Consume data in advance of what the decompressor requires.

This routine can be called at any time after initializing the JPEG object. It reads some additional data and returns when one of the indicated significant events occurs. If called after the EOI marker is reached, it will immediately return ReadResult.JPEG_REACHED_EOI without attempting to read more data.

Initializes the compression object with default parameters, then copy from the source object all parameters needed for lossless transcoding.

Parameters that can be varied without loss (such as scan script and Huffman optimization) are left in their default states.

Initializes a new instance of the jpeg_decompress_struct class.

Initializes a new instance of the jpeg_decompress_struct class.

Finish JPEG decompression.

This will normally just verify the file trailer and release temp storage.

Finish up after an output pass in buffered-image mode.

Is there more than one scan?

If you are concerned about maximum performance on baseline JPEG files, you should use buffered-image mode only when the incoming file actually has multiple scans. This can be tested by calling this method.

Indicates if we have finished reading the input file.

Read or write the raw DCT coefficient arrays from a JPEG file (useful for lossless transcoding).

jpeg_read_header must be completed before calling this.
The entire image is read into a set of virtual coefficient-block arrays, one per component. The return value is an array of virtual-array descriptors.
An alternative usage is to simply obtain access to the coefficient arrays during a buffered-image mode decompression operation. This is allowed after any jpeg_finish_output call. The arrays can be accessed until jpeg_finish_decompress is called. Note that any call to the library may reposition the arrays, so don't rely on jvirt_array{T}.Access results to stay valid across library calls.

Decompression startup: this will read the source datastream header markers, up to the beginning of the compressed data proper.

Need only initialize JPEG object and supply a data source before calling.
On return, the image dimensions and other info have been stored in the JPEG object. The application may wish to consult this information before selecting decompression parameters.
This routine is now just a front end to jpeg_consume_input, with some extra error checking.

Alternate entry point to read raw data.

Replaces jpeg_read_scanlines when reading raw downsampled data. Processes exactly one iMCU row per call, unless suspended.

Read some scanlines of data from the JPEG decompressor.

We warn about excess calls to jpeg_read_scanlines since this likely signals an application programmer error. However, an oversize buffer (max_lines > scanlines remaining) is not an error.

Control saving of COM and APPn markers into Marker_list.

Sets processor for special marker.

Allows you to supply your own routine to process COM and/or APPn markers on-the-fly as they are read.

Decompression initialization.

jpeg_read_header must be completed before calling this.
If a multipass operating mode was selected, this will do all but the last pass, and thus may take a great deal of time.

Initialize for an output pass in buffered-image mode.

Sets input stream.

The caller must have already opened the stream, and is responsible for closing it after finishing decompression.

Set default decompression parameters.

Initialization of JPEG compression objects. The error manager must already be set up (in case memory manager fails).

Set up for an output pass, and perform any dummy pass(es) needed. Common subroutine for jpeg_start_decompress and jpeg_start_output. Entry: global_state = DSTATE_PRESCAN only if previously suspended. Exit: If done, returns true and sets global_state for proper output mode. If suspended, returns false and sets global_state = DSTATE_PRESCAN.

Master selection of decompression modules for transcoding (that is, reading raw DCT coefficient arrays from an input JPEG file.) This substitutes for initialization of the full decompressor.

Determine whether merged upsample/color conversion should be used. CRUCIAL: this must match the actual capabilities of merged upsampler!