如何在C ++中操纵/旋转JPEG图像？ [英] How can I manipulate/rotate a JPEG image in C++?

问题描述

我想使用编译的libjpeg-9 example.c和transupp.c代码和库在Eclipse项目中旋转.jpg图片。

I'd like to use the compiled libjpeg-9 example.c and transupp.c code and libraries to rotate a .jpg image in an Eclipse project.

从一开始就实现此目标的工作进度：在Windows for Eclipse中编译/使用libjpeg

Working progress on achieving this from the start: Compiling/using libjpeg in Windows for Eclipse

尝试将do_rot_180和读/写功能集成到一个位置： jcopy_block_row无法解析+ wierd eclipse行为 transupp中的

Trying to integrate do_rot_180 and read/write functions into one location: jcopy_block_row cannot be resolved + wierd eclipse behavior

推荐答案

do_rot_180 在 libjpeg （你知道它是Q有标签）正在做你想要的。

do_rot_180 function in transupp.c in libjpeg (you are aware of it as the Q has the tag) is doing exactly what you want.

LOCAL(void)
do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
        jvirt_barray_ptr *src_coef_arrays,
        jvirt_barray_ptr *dst_coef_arrays)
/* 180 degree rotation is equivalent to
 *   1. Vertical mirroring;
 *   2. Horizontal mirroring.
 * These two steps are merged into a single processing routine.
 */

该函数由 jtransform_execute_transformation / JXFORM_ROT_180 和loslessy重新排序JPEG的内部实现旋转效果。 此功能演示了使用和旋转给定文件，使用指定的转换（角度）写入一个新的修改文件。

The function is used by jtransform_execute_transformation/JXFORM_ROT_180 and loslessy reorders JPEG's internals to achieve rotation effect. This function demonstrates the use and rotates a given file and writes a new modified file using specified transformation (angle).

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