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图片高级压缩

最近更新时间:2021-12-13 12:11:08

简介

本文档提供关于图片高级压缩的 API 概览以及 SDK 示例代码。

API 操作描述
图片高级压缩 图片高级压缩可以更加高效地将图片转换为 TPG 或 HEIF 等高压缩比格式,有效降低图片传输链路及加载耗时,降低带宽及流量成本

方法原型

通过下载对象方法实现,用户只需要添加请求参数,请求参数格式如下,关于下载对象详细说明请参见 下载对象

imageMogr2/format/<Format>
| 参数 | 含义 |
| :--------- | :--------------------------------------------- |
| format | 压缩格式,目标缩略图的图片格式为 TPG 或 HEIF。 |

请求示例

#include "cos_http_io.h"
#include "cos_api.h"
#include "cos_log.h"
#include <unistd.h>

// endpoint 是 COS 访问域名信息,详情请参见 https://cloud.tencent.com/document/product/436/6224 文档
static char TEST_COS_ENDPOINT[] = "cos.ap-guangzhou.myqcloud.com";
// 开发者拥有的项目身份ID/密钥,可在 https://console.cloud.tencent.com/cam/capi 页面获取
static char *TEST_ACCESS_KEY_ID;                //your secret_id
static char *TEST_ACCESS_KEY_SECRET;            //your secret_key
// 开发者访问 COS 服务时拥有的用户维度唯一资源标识,用以标识资源,可在 https://console.cloud.tencent.com/cam/capi 页面获取
static char TEST_APPID[] = "<APPID>";    //your appid
//the cos bucket name, syntax: [bucket]-[appid], for example: mybucket-1253666666,可在 https://console.cloud.tencent.com/cos5/bucket 查看
static char TEST_BUCKET_NAME[] = "<bucketname-appid>"; 

void log_status(cos_status_t *s)
{
    cos_warn_log("status->code: %d", s->code);
    if (s->error_code) cos_warn_log("status->error_code: %s", s->error_code);
    if (s->error_msg) cos_warn_log("status->error_msg: %s", s->error_msg);
    if (s->req_id) cos_warn_log("status->req_id: %s", s->req_id);
}

void init_test_config(cos_config_t *config, int is_cname)
{
    cos_str_set(&config->endpoint, TEST_COS_ENDPOINT);
    cos_str_set(&config->access_key_id, TEST_ACCESS_KEY_ID);
    cos_str_set(&config->access_key_secret, TEST_ACCESS_KEY_SECRET);
    cos_str_set(&config->appid, TEST_APPID);
    config->is_cname = is_cname;
}

void init_test_request_options(cos_request_options_t *options, int is_cname)
{
    options->config = cos_config_create(options->pool);
    init_test_config(options->config, is_cname);
    options->ctl = cos_http_controller_create(options->pool, 0);
}

void test_image_compress()
{
    cos_pool_t *p = NULL;
    int is_cname = 0; 
    cos_status_t *s = NULL;
    cos_request_options_t *options = NULL;
    cos_string_t bucket;
    cos_string_t object;
    cos_string_t file;
    cos_table_t *resp_headers;
    cos_table_t *params = NULL;

    cos_pool_create(&p, NULL);
    options = cos_request_options_create(p);
    init_test_request_options(options, is_cname);
    cos_str_set(&bucket, TEST_BUCKET_NAME);

    params = cos_table_make(p, 1);
    apr_table_addn(params, "imageMogr2/format/tpg", "");
    cos_str_set(&object, "test.jpg");
    cos_str_set(&file, "test.tpg");
    s = cos_get_object_to_file(options, &bucket, &object, NULL, params, &file, &resp_headers);
    log_status(s);
    if (!cos_status_is_ok(s)) {
        printf("cos_get_object_to_file fail, req_id:%s\n", s->req_id);
    }

    params = cos_table_make(p, 1);
    apr_table_addn(params, "imageMogr2/format/heif", "");
    cos_str_set(&file, "test.heif");
    s = cos_get_object_to_file(options, &bucket, &object, NULL, params, &file, &resp_headers);
    log_status(s);
    if (!cos_status_is_ok(s)) {
        printf("cos_get_object_to_file fail, req_id:%s\n", s->req_id);
    }

    cos_pool_destroy(p);
}

int main(int argc, char *argv[])
{
    // 通过环境变量获取 SECRETID 和 SECRETKEY
    TEST_ACCESS_KEY_ID     = getenv("COS_SECRETID");
    TEST_ACCESS_KEY_SECRET = getenv("COS_SECRETKEY");

    if (cos_http_io_initialize(NULL, 0) != COSE_OK) {
       exit(1);
    }

    //set log level, default COS_LOG_WARN
    cos_log_set_level(COS_LOG_WARN);

    //set log output, default stderr
    cos_log_set_output(NULL);

    test_image_compress();

    cos_http_io_deinitialize();

    return 0;
}