使用 Cocoa 的 Photoshop 插件 - 如何获取预览

Question

我正在 Mac 上实现一个 Photoshop 插件，并且使用 Cocoa 来实现。 到目前为止一切正常，但下一步是提供“预览”图像，作为我的插件窗口的一部分，但我陷入了困境。 我是一个 n00b Obj-C 程序员，这并没有真正帮助:-)

到目前为止我已经得到了这样的东西：

int dataSize = gFilterRecord->bigDocumentData->wholeSize32.v *
               gFilterRecord->bigDocumentData->wholeSize32.h *
               gFilterRecord->planes; 

NSData *inData = [[NSData alloc] initWithBytesNoCopy:gFilterRecord->inData length:dataSize freeWhenDone:NO];
NSLog(@"LoadImageFromSDK : Data created");
NSImage *imageTmp = [[NSImage alloc] initWithData:inData];
NSLog(@"LoadImageFromSDK : Image created");

//Save to PNG file as a test of this image creation
[[imageTmp TIFFRepresentation] writeToFile:@"/tmp/imageTmp.tif" atomically:YES];
NSLog(@"LoadImageFromSDK : Wrote image to disk");

目前，它严重崩溃了：
09/07/22 10:23:32 AM Adob​​e Photoshop Elements[46628] *** NSCopyMemoryPages(0x0, 0x245f4000, 2265088) 失败

我可能错误地计算了 inData 的大小。 帮助？

另外， NSImage 是否能够正确解释该图像数据块？ 或者我应该放弃它，只对 NSImage 进行逐像素映射？

Answer 1

好吧，弄清楚这一点比我预想的要痛苦得多。 另外，感谢 NVidia 发布此 PDF，这是对 Photoshop SDK 过滤器记录的解释比实际的 SDK 文档更好。

除了用于调试目的的示例 tif 文件之外，此代码实际上读取 inData 并生成一个可用的 NSImage（大量日志记录只是为了弄清楚它在做什么，请随意删除）。

NSLog(@"Entering LoadImageFromSDK");

unsigned char *bitmapPlanes[4];    
bitmapPlanes[0] = (unsigned char *) (gFilterRecord->inData);

NSLog(@"Params to create bitmap");
NSLog(@"pixelsWide = %d", gFilterRecord->bigDocumentData->imageSize32.h );
NSLog(@"pixelsHigh = %d", gFilterRecord->bigDocumentData->imageSize32.v );
NSLog(@"bitsPerSample = %d", gFilterRecord->depth );
NSLog(@"samplesPerPixel = %d", gFilterRecord->planes );
NSLog(@"hasAlpha = %d", NO );
NSLog(@"isPlanar = %d", NO );
NSLog(@"colorSpaceName = %@", mapImageModeToColorSpace(gFilterRecord->imageMode) );
NSLog(@"bytesPerRow = %d", gFilterRecord->inRowBytes );
NSLog(@"bitsPerPixel = %d", gFilterRecord->depth*gFilterRecord->planes );    

NSBitmapImageRep *bitmapTmp = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:bitmapPlanes
                                                                      pixelsWide:gFilterRecord->bigDocumentData->imageSize32.h
                                                                      pixelsHigh:gFilterRecord->bigDocumentData->imageSize32.v
                                                                   bitsPerSample:gFilterRecord->depth
                                                                 samplesPerPixel:gFilterRecord->planes
                                                                        hasAlpha:NO 
                                                                        isPlanar:NO 
                                                                  colorSpaceName:mapImageModeToColorSpace(gFilterRecord->imageMode) 
                                                                     bytesPerRow:gFilterRecord->inRowBytes
                                                                    bitsPerPixel:gFilterRecord->depth*gFilterRecord->planes];

NSLog(@"LoadImageFromSDK : Bitmap created = %@", bitmapTmp);

[[bitmapTmp TIFFRepresentation] writeToFile:@"/Users/someuser/temp/sample.tif" atomically:YES];


NSImage *imageTmp = [[NSImage alloc] initWithSize:[bitmapTmp size]];
[imageTmp addRepresentation:bitmapTmp];
NSLog(@"LoadImageFromSDK : Image created = %@", imageTmp);