PS新建画布后，如何更改大小

[[{"txt": "\u6709\u65f6\u5019\u753b\u5e03\u8bbe\u7f6e\u5c0f\u4e86\uff0c\u6216\u8005\u8bbe\u7f6e\u6253\u4e86\uff0c\u8fd9\u65f6\u5019\u8be5\u600e\u4e48\u529e\uff0c\u8d76\u7d27\u5f80\u4e0b\u770b\u3002"}], [{"txt": ["\u5de5\u5177/\u539f\u6599"]}, {"txt": "Adobe Photoshop CC2018"}, {"txt": "\u7535\u8111"}], [{"txt": ["\u65b9\u6cd5/\u6b65\u9aa4"]}, {"txt": "\u70b9\u51fb\u56fe\u50cf--\u753b\u5e03\u5927\u5c0f\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/05aae8a75f0f822b21c16887c018512c8df14d84.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u6b64\u5904\u53ef\u8bbe\u7f6e\u957f\u5ea6\u548c\u5bbd\u5ea6\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/506d92f1d8a7263314abb956c02c56ee7a7f4484.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u6b64\u5904\u53ef\u4fee\u6539\u80cc\u666f\u989c\u8272\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/57af657f860e7c7586db8840650d3aceabd7bf84.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u8bbe\u7f6e\u5b8c\u6210\u540e\uff0c\u70b9\u51fb\u786e\u5b9a\u5373\u53ef\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/3b8fb4d7726b0ce20fc840baef781423bfb9b684.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u89c2\u5bdf\u7ed3\u679c\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/65390a23beb9763e51edcf636ad06de89b61b084.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}], [{"txt": ["\u6ce8\u610f\u4e8b\u9879"]}, {"txt": "\u5176\u4ed6\u65b9\u6cd5\u4e5f\u53ef\u4ee5\u5236\u4f5c\u51fa\u6765\uff0c\u60f3\u5b66\u4e60\u66f4\u591a\u65b9\u6cd5\uff0c\u6b22\u8fce\u5173\u6ce8\u3002"}]]