Hello, i'm trying to convert a float array to a greyscale PNG with a NSBitmapImageRep but i doesn't work and all i get is a blank png (just white).
To test the feasibility of my idea i created a float array of size 55*77 with half filled with 1500. and the other half filled with 3000. Theorically i should obtain a PNG that looks like the picture in the following link : http://www.hostingpics.net/viewer.php?id=315752capture.png Here is the source code that i use : /************************************ Code begin ******************************************/ //load the floating point array NSData * binaryData=[NSData dataWithContentsOfFile:binaryPath]; //binary is just a 32bits array full of 1500. and 3000. as described previously //get a pointer datapointer = (unsigned char *) [binaryData bytes]; //convert the array into a NSBitmapImageRep NSBitmapImageRep * bitmap = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:&datapointer pixelsWide:sx pixelsHigh:sz bitsPerSample:32 samplesPerPixel:1 hasAlpha:NO isPlanar:NO colorSpaceName:NSCalibratedWhiteColorSpace bitmapFormat:NSFloatingPointSamplesBitmapFormat bytesPerRow:4*sx bitsPerPixel:32]; //save it to png format NSData * tow = [bitmap representationUsingType:NSPNGFileType properties:nil]; [tow writeToFile:@"/Users/Perif/Desktop/img.png" atomically:NO]; /************************************Code End******************************************/ My questions are : Is this the proper way to do what i want (convert a 32bits float array to a greyscale PNG) ? What is my error ? Thanks a lot for your help. Perif _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
