{"resolved":true,"match_type":"uuid","source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","requested_by":"printed_page","book":{"source_type":"original_book","book_id":"38270854-596f-4a26-8183-db8c968c6020","id":"38270854-596f-4a26-8183-db8c968c6020","uuid":"38270854-596f-4a26-8183-db8c968c6020","title":"编码 隐匿在计算机软硬件背后的语言","normalized_title":"编码隐匿在计算机软硬件背后的语言","author":null,"edition":null,"publisher":null,"year":null,"isbn":"9787121181184","isbns":["9787121181184","0123456789","6044921875","3039331000","0000000000","0000000000000"],"parsed":true,"ai_readable":true,"document_type":"book","page_count":438,"navigation_url":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020","title_url":"https://workshop.closeclaw.top/ai/title/%E7%BC%96%E7%A0%81%20%E9%9A%90%E5%8C%BF%E5%9C%A8%E8%AE%A1%E7%AE%97%E6%9C%BA%E8%BD%AF%E7%A1%AC%E4%BB%B6%E8%83%8C%E5%90%8E%E7%9A%84%E8%AF%AD%E8%A8%80","fixed_page_url_template":"https://workshop.closeclaw.top/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","path_api_url_template":"https://workshop.closeclaw.top/api/ai/book/38270854-596f-4a26-8183-db8c968c6020/page/{printed_page}","read_url":"https://workshop.closeclaw.top/api/ai/read/38270854-596f-4a26-8183-db8c968c6020","page_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/page","search_url":"https://workshop.closeclaw.top/api/ai/books/38270854-596f-4a26-8183-db8c968c6020/search"},"page":{"printed_page":81,"pdf_page":97,"physical_index":97,"physical_index_base":0,"printed_page_status":"recognized","page_sha256":"bec9ed713129ed05e4d087a9465cc7e4ae6207e3525d714ed4d93a44417cae77"},"chapter":"编码隐匿在计算机软硬件背后的语言","content":"$$\n\\begin{array} { c c c } { { 1 6 0 0 } } & { { \\quad 2 0 0 0 } } & { { \\quad 2 5 0 0 } } \\\\ { { } } & { { } } & { { } } \\\\ { { 3 2 0 0 } } & { { \\quad 4 0 0 0 } } & { { \\quad 5 0 0 0 } } \\end{array}\n$$\n\n要对ASA等级进行编码需要多少个比特位呢？答案是5个。我们知道 $2 ^ { 4 }$ 是16，比24要小。 $2 ^ { 5 }$ 是32，而这个数又超过了所需的码字数。\n\n与胶片速度对应的比特值如下表所示。\n\n大多数现代的35毫米照相机胶片都使用这些码字（除了那些要手动进行曝光的相机和具有内置式测光表但需要手动设定曝光速度的相机以外)。如果你观察一下照相机内部放胶卷的地方，就会发现在胶卷筒内部有6个金属的触点，对应着胶片的金属方格（1\\~6号)。银色方格实际上是胶卷暗盒中的金属，即导体；涂有颜料的黑色方格，是绝缘体。\n\n9 二进制数\n\n81","previous_page":80,"next_page":82}