--- transupp.h.orig Wed Jul 23 22:39:12 1997
+++ transupp.h Fri Jun 4 15:07:31 2004
@@ -1,7 +1,7 @@
/*
* transupp.h
*
- * Copyright (C) 1997, Thomas G. Lane.
+ * Copyright (C) 1997-2001, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
@@ -22,32 +22,6 @@
#define TRANSFORMS_SUPPORTED 1 /* 0 disables transform code */
#endif
-/* Short forms of external names for systems with brain-damaged linkers. */
-
-#ifdef NEED_SHORT_EXTERNAL_NAMES
-#define jtransform_request_workspace jTrRequest
-#define jtransform_adjust_parameters jTrAdjust
-#define jtransform_execute_transformation jTrExec
-#define jcopy_markers_setup jCMrkSetup
-#define jcopy_markers_execute jCMrkExec
-#endif /* NEED_SHORT_EXTERNAL_NAMES */
-
-
-/*
- * Codes for supported types of image transformations.
- */
-
-typedef enum {
- JXFORM_NONE, /* no transformation */
- JXFORM_FLIP_H, /* horizontal flip */
- JXFORM_FLIP_V, /* vertical flip */
- JXFORM_TRANSPOSE, /* transpose across UL-to-LR axis */
- JXFORM_TRANSVERSE, /* transpose across UR-to-LL axis */
- JXFORM_ROT_90, /* 90-degree clockwise rotation */
- JXFORM_ROT_180, /* 180-degree rotation */
- JXFORM_ROT_270 /* 270-degree clockwise (or 90 ccw) */
-} JXFORM_CODE;
-
/*
* Although rotating and flipping data expressed as DCT coefficients is not
* hard, there is an asymmetry in the JPEG format specification for images
@@ -75,6 +49,19 @@
* (For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim
* followed by -rot 180 -trim trims both edges.)
*
+ * We also offer a lossless-crop option, which discards data outside a given
+ * image region but losslessly preserves what is inside. Like the rotate and
+ * flip transforms, lossless crop is restricted by the JPEG format: the upper
+ * left corner of the selected region must fall on an iMCU boundary. If this
+ * does not hold for the given crop parameters, we silently move the upper left
+ * corner up and/or left to make it so, simultaneously increasing the region
+ * dimensions to keep the lower right crop corner unchanged. (Thus, the
+ * output image covers at least the requested region, but may cover more.)
+ *
+ * If both crop and a rotate/flip transform are requested, the crop is applied
+ * last --- that is, the crop region is specified in terms of the destination
+ * image.
+ *
* We also offer a "force to grayscale" option, which simply discards the
* chrominance channels of a YCbCr image. This is lossless in the sense that
* the luminance channel is preserved exactly. It's not the same kind of
@@ -83,20 +70,96 @@
* be aware of the option to know how many components to work on.
*/
+
+/* Short forms of external names for systems with brain-damaged linkers. */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jtransform_parse_crop_spec jTrParCrop
+#define jtransform_request_workspace jTrRequest
+#define jtransform_adjust_parameters jTrAdjust
+#define jtransform_execute_transform jTrExec
+#define jtransform_perfect_transform jTrPerfect
+#define jcopy_markers_setup jCMrkSetup
+#define jcopy_markers_execute jCMrkExec
+#endif /* NEED_SHORT_EXTERNAL_NAMES */
+
+
+/*
+ * Codes for supported types of image transformations.
+ */
+
+typedef enum {
+ JXFORM_NONE, /* no transformation */
+ JXFORM_FLIP_H, /* horizontal flip */
+ JXFORM_FLIP_V, /* vertical flip */
+ JXFORM_TRANSPOSE, /* transpose across UL-to-LR axis */
+ JXFORM_TRANSVERSE, /* transpose across UR-to-LL axis */
+ JXFORM_ROT_90, /* 90-degree clockwise rotation */
+ JXFORM_ROT_180, /* 180-degree rotation */
+ JXFORM_ROT_270, /* 270-degree clockwise (or 90 ccw) */
+ JXFORM_DROP /* drop */
+} JXFORM_CODE;
+
+/*
+ * Codes for crop parameters, which can individually be unspecified,
+ * positive, or negative. (Negative width or height makes no sense, though.)
+ */
+
+typedef enum {
+ JCROP_UNSET,
+ JCROP_POS,
+ JCROP_NEG
+} JCROP_CODE;
+
+/*
+ * Transform parameters struct.
+ * NB: application must not change any elements of this struct after
+ * calling jtransform_request_workspace.
+ */
+
typedef struct {
/* Options: set by caller */
JXFORM_CODE transform; /* image transform operator */
+ boolean perfect; /* if TRUE, fail if partial MCUs are requested */
boolean trim; /* if TRUE, trim partial MCUs as needed */
boolean force_grayscale; /* if TRUE, convert color image to grayscale */
+ boolean crop; /* if TRUE, crop source image */
+
+ /* Crop parameters: application need not set these unless crop is TRUE.
+ * These can be filled in by jtransform_parse_crop_spec().
+ */
+ JDIMENSION crop_width; /* Width of selected region */
+ JCROP_CODE crop_width_set;
+ JDIMENSION crop_height; /* Height of selected region */
+ JCROP_CODE crop_height_set;
+ JDIMENSION crop_xoffset; /* X offset of selected region */
+ JCROP_CODE crop_xoffset_set; /* (negative measures from right edge) */
+ JDIMENSION crop_yoffset; /* Y offset of selected region */
+ JCROP_CODE crop_yoffset_set; /* (negative measures from bottom edge) */
+
+ /* Drop parameters: set by caller for drop request */
+ j_decompress_ptr drop_ptr;
+ jvirt_barray_ptr * drop_coef_arrays;
/* Internal workspace: caller should not touch these */
int num_components; /* # of components in workspace */
jvirt_barray_ptr * workspace_coef_arrays; /* workspace for transformations */
+ JDIMENSION output_width; /* cropped destination dimensions */
+ JDIMENSION output_height;
+ JDIMENSION x_crop_offset; /* destination crop offsets measured in iMCUs */
+ JDIMENSION y_crop_offset;
+ JDIMENSION drop_width; /* drop dimensions measured in iMCUs */
+ JDIMENSION drop_height;
+ int max_h_samp_factor; /* destination iMCU size */
+ int max_v_samp_factor;
} jpeg_transform_info;
#if TRANSFORMS_SUPPORTED
+/* Parse a crop specification (written in X11 geometry style) */
+EXTERN(boolean) jtransform_parse_crop_spec
+ JPP((jpeg_transform_info *info, const char *spec));
/* Request any required workspace */
EXTERN(void) jtransform_request_workspace
JPP((j_decompress_ptr srcinfo, jpeg_transform_info *info));
@@ -106,10 +169,24 @@
jvirt_barray_ptr *src_coef_arrays,
jpeg_transform_info *info));
/* Execute the actual transformation, if any */
-EXTERN(void) jtransform_execute_transformation
+EXTERN(void) jtransform_execute_transform
JPP((j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
jvirt_barray_ptr *src_coef_arrays,
jpeg_transform_info *info));
+/* Determine whether lossless transformation is perfectly
+ * possible for a specified image and transformation.
+ */
+EXTERN(boolean) jtransform_perfect_transform
+ JPP((JDIMENSION image_width, JDIMENSION image_height,
+ int MCU_width, int MCU_height,
+ JXFORM_CODE transform));
+
+/* jtransform_execute_transform used to be called
+ * jtransform_execute_transformation, but some compilers complain about
+ * routine names that long. This macro is here to avoid breaking any
+ * old source code that uses the original name...
+ */
+#define jtransform_execute_transformation jtransform_execute_transform
#endif /* TRANSFORMS_SUPPORTED */
@@ -121,7 +198,8 @@
typedef enum {
JCOPYOPT_NONE, /* copy no optional markers */
JCOPYOPT_COMMENTS, /* copy only comment (COM) markers */
- JCOPYOPT_ALL /* copy all optional markers */
+ JCOPYOPT_ALL, /* copy all optional markers */
+ JCOPYOPT_EXIF /* copy Exif APP1 marker */
} JCOPY_OPTION;
#define JCOPYOPT_DEFAULT JCOPYOPT_COMMENTS /* recommended default */
