Overview

This document provides an overview of APIs and SDK code samples related to advanced image compression.

Method prototype

Image compression is implemented via object download. All you need to do is adding the request parameters in the following syntax:

imageMogr2/format/<Format>

Sample request

#include "cos_http_io.h"
#include "cos_api.h"
#include "cos_log.h"
#include <unistd.h>
// `endpoint` is the COS access domain name. For more information, visit https://intl.cloud.tencent.com/document/product/1045.
static char TEST_COS_ENDPOINT[] = "cos.ap-guangzhou.myqcloud.com";
// A developer-owned secret ID/key used for the project. It can be obtained at https://console.cloud.tencent.com/cam/capi.
static char *TEST_ACCESS_KEY_ID;                //your secret_id
static char *TEST_ACCESS_KEY_SECRET;            //your secret_key
// A unique user-level resource identifier for COS access. It can be obtained at https://console.cloud.tencent.com/cam/capi.
static char TEST_APPID[] = "<APPID>";    //your appid
// COS bucket name, in the format of [bucket]-[appid], for example `mybucket-1253666666`. It can be obtained at https://console.cloud.tencent.com/cos5/bucket.
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[])
{
  // Get SecretId and SecretKey from environment variables
  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;
}