Transferring C64 Pictures
Many of of my C64 pictures were originally transferred from the C64 into an Amiga C64 emulator.
To do this there was a special lead which connected a C64 Disk drive to the Amiga C64 emulator. Once the drive was connected you could access it from the emulator just like a normal disk. You could also save the files directly onto an Amiga floppy or hard disk.
Once I had my pictures on an Amiga floppy, I used a program to convert the Koala pad files to Amiga .IFF format. Later the pictures were transferred onto the PC using an Amiga to MS-DOS converter program and converted in to BMP/GIF format.
Nowadays you can buy leads to connect a C64 disk drive to the parallel port of your computer and transfer the files directly to a PC. There are several converter programs out there that can directly convert C64 format artwork into standard image formats like .bmp and .gif.
Some of my pictures have been transferred by loading the C64 programs that contained them into a C64 emulator, then snapshotted using the emulator screenshot feature. Others I hacked out of an Amiga demo.