O Image Processing é um serviço escalável, seguro, econômico e altamente confiável fornecido pelo Object Storage Service (OSS). Após enviar uma imagem original para o OSS, é possível processá-la a qualquer momento, de qualquer lugar e em qualquer dispositivo conectado à Internet por meio de APIs RESTful simples.
Observações
Este tópico utiliza o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços da Alibaba Cloud na mesma região, use um endpoint interno. Para obter mais informações sobre as regiões e endpoints do OSS, consulte Regions and endpoints.
Este tópico demonstra como criar uma instância OSSClient com um endpoint do OSS. Para configurações alternativas, como usar um domínio personalizado ou autenticar-se com credenciais do Security Token Service (STS), consulte Initialization (C SDK).
Processar imagens usando parâmetros de processamento de imagem
Processar uma imagem com um único parâmetro e salvá-la como um arquivo local
#include "oss_api.h"
#include "aos_http_io.h"
/* Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Replace with your bucket name, for example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Replace with the full path of the object. The full path cannot contain the bucket name. For example, exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
/* Replace yourRegion with the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
options->config = oss_config_create(options->pool);
/* Initialize an aos_string_t type with a char* string. */
aos_str_set(&options->config->endpoint, endpoint);
/* Obtain access credentials from environment variables. Before running this sample code, make sure the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
// Configure the following two additional parameters.
aos_str_set(&options->config->region, region);
options->config->signature_version = 4;
/* Specifies whether a CNAME is used. 0 indicates that no CNAME is used. */
options->config->is_cname = 0;
/* Set network parameters, such as the timeout period. */
options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
/* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
exit(1);
}
/* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */
aos_pool_t *pool;
/* Create a new memory pool. The second parameter is NULL, which indicates that the new pool does not inherit from another memory pool. */
aos_pool_create(&pool, NULL);
/* Create and initialize options. This parameter includes global configuration information such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */
oss_request_options_t *oss_client_options;
/* Allocate memory from the memory pool to options. */
oss_client_options = oss_request_options_create(pool);
/* Initialize the client options oss_client_options. */
init_options(oss_client_options);
/* Initialize parameters. */
aos_string_t bucket;
aos_string_t object;
aos_string_t file;
aos_table_t *headers = NULL;
aos_table_t *params = NULL;
aos_table_t *resp_headers = NULL;
aos_status_t *resp_status = NULL;
aos_str_set(&bucket, bucket_name);
aos_str_set(&object, object_name);
/* Resize the image to a fixed width and height of 100 px. */
params = aos_table_make(pool, 1);
apr_table_set(params, OSS_PROCESS, "image/resize,m_fixed,w_100,h_100");
/* Save the processed image to a local file. */
aos_str_set(&file, "yourLocalFileName");
resp_status = oss_get_object_to_file(oss_client_options, &bucket, &object, headers, params, &file, &resp_headers);
if (aos_status_is_ok(resp_status)) {
printf("get object to file succeeded\n");
} else {
printf("get object to file failed\n");
}
/* Release the memory pool. This is equivalent to releasing the memory allocated to resources during the request. */
aos_pool_destroy(pool);
/* Release the previously allocated global resources. */
aos_http_io_deinitialize();
return 0;
}
Processar uma imagem com vários parâmetros e salvá-la como um arquivo local
Ao usar vários parâmetros de processamento de imagem, separe-os com barras (/).
#include "oss_api.h"
#include "aos_http_io.h"
/* Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Replace with your bucket name, for example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Replace with the full path of the object. The full path cannot contain the bucket name. For example, exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
/* Replace yourRegion with the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
options->config = oss_config_create(options->pool);
/* Initialize an aos_string_t type with a char* string. */
aos_str_set(&options->config->endpoint, endpoint);
/* Obtain access credentials from environment variables. Before running this sample code, make sure the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
// Configure the following two additional parameters.
aos_str_set(&options->config->region, region);
options->config->signature_version = 4;
/* Specifies whether a CNAME is used. 0 indicates that no CNAME is used. */
options->config->is_cname = 0;
/* Set network parameters, such as the timeout period. */
options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
/* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
exit(1);
}
/* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */
aos_pool_t *pool;
/* Create a new memory pool. The second parameter is NULL, which indicates that the new pool does not inherit from another memory pool. */
aos_pool_create(&pool, NULL);
/* Create and initialize options. This parameter includes global configuration information such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */
oss_request_options_t *oss_client_options;
/* Allocate memory from the memory pool to options. */
oss_client_options = oss_request_options_create(pool);
/* Initialize the client options oss_client_options. */
init_options(oss_client_options);
/* Initialize parameters. */
aos_string_t bucket;
aos_string_t object;
aos_string_t file;
aos_table_t *headers = NULL;
aos_table_t *params = NULL;
aos_table_t *resp_headers = NULL;
aos_status_t *resp_status = NULL;
aos_str_set(&bucket, bucket_name);
aos_str_set(&object, object_name);
/* Resize the image to a fixed width and height of 100 px, and then rotate it by 90 degrees. */
params = aos_table_make(pool, 1);
apr_table_set(params, OSS_PROCESS, "image/resize,m_fixed,w_100,h_100/rotate,90");
/* Save the processed image to a local file. */
aos_str_set(&file, "yourLocalFileName");
resp_status = oss_get_object_to_file(oss_client_options, &bucket, &object, headers, params, &file, &resp_headers);
if (aos_status_is_ok(resp_status)) {
printf("get object to file succeeded\n");
} else {
printf("get object to file failed\n");
}
/* Release the memory pool. This is equivalent to releasing the memory allocated to resources during the request. */
aos_pool_destroy(pool);
/* Release the previously allocated global resources. */
aos_http_io_deinitialize();
return 0;
}
Processar imagens usando estilos de imagem
-
Crie um estilo de imagem.
É possível incluir vários parâmetros de processamento de imagem em um estilo para executar operações complexas rapidamente. Para obter mais informações, consulte Image styles.
-
Processe uma imagem usando um estilo de imagem.
#include "oss_api.h" #include "aos_http_io.h" /* Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */ const char *endpoint = "yourEndpoint"; /* Replace with your bucket name, for example, examplebucket. */ const char *bucket_name = "examplebucket"; /* Replace with the full path of the object. The full path cannot contain the bucket name. For example, exampledir/exampleobject.txt. */ const char *object_name = "exampledir/exampleobject.txt"; /* Replace yourRegion with the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */ const char *region = "yourRegion"; void init_options(oss_request_options_t *options) { options->config = oss_config_create(options->pool); /* Initialize an aos_string_t type with a char* string. */ aos_str_set(&options->config->endpoint, endpoint); /* Obtain access credentials from environment variables. Before running this sample code, make sure the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */ aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID")); aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET")); // Configure the following two additional parameters. aos_str_set(&options->config->region, region); options->config->signature_version = 4; /* Specifies whether a CNAME is used. 0 indicates that no CNAME is used. */ options->config->is_cname = 0; /* Set network parameters, such as the timeout period. */ options->ctl = aos_http_controller_create(options->pool, 0); } int main(int argc, char *argv[]) { /* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */ if (aos_http_io_initialize(NULL, 0) != AOSE_OK) { exit(1); } /* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */ aos_pool_t *pool; /* Create a new memory pool. The second parameter is NULL, which indicates that the new pool does not inherit from another memory pool. */ aos_pool_create(&pool, NULL); /* Create and initialize options. This parameter includes global configuration information such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */ oss_request_options_t *oss_client_options; /* Allocate memory from the memory pool to options. */ oss_client_options = oss_request_options_create(pool); /* Initialize the client options oss_client_options. */ init_options(oss_client_options); /* Initialize parameters. */ aos_string_t bucket; aos_string_t object; aos_string_t file; aos_table_t *headers = NULL; aos_table_t *params = NULL; aos_table_t *resp_headers = NULL; aos_status_t *resp_status = NULL; aos_str_set(&bucket, bucket_name); aos_str_set(&object, object_name); /* Specify an image style. */ params = aos_table_make(pool, 1); /* Replace yourCustomStyleName with the name of the image style that you created in Step 1. */ apr_table_set(params, OSS_PROCESS, "style/yourCustomStyleName"); /* Save the processed image to a local file. */ aos_str_set(&file, "yourLocalFileName"); resp_status = oss_get_object_to_file(oss_client_options, &bucket, &object, headers, params, &file, &resp_headers); if (aos_status_is_ok(resp_status)) { printf("get object to file succeeded\n"); } else { printf("get object to file failed\n"); } /* Release the memory pool. This is equivalent to releasing the memory allocated to resources during the request. */ aos_pool_destroy(pool); /* Release the previously allocated global resources. */ aos_http_io_deinitialize(); return 0; }
Gerar uma URL assinada para um arquivo com parâmetros de processamento de imagem
É necessário assinar as URLs de acesso a arquivos privados. Como o OSS não permite adicionar parâmetros de processamento de imagem diretamente a uma URL assinada, adicione esses parâmetros à assinatura para processar um arquivo privado.
#include "oss_api.h"
#include "aos_http_io.h"
/* Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Replace with your bucket name, for example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Replace with the full path of the object. The full path cannot contain the bucket name. For example, exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
/* Replace yourRegion with the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
options->config = oss_config_create(options->pool);
/* Initialize an aos_string_t type with a char* string. */
aos_str_set(&options->config->endpoint, endpoint);
/* Obtain access credentials from environment variables. Before running this sample code, make sure the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */
aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
// Configure the following two additional parameters.
aos_str_set(&options->config->region, region);
options->config->signature_version = 4;
/* Specifies whether a CNAME is used. 0 indicates that no CNAME is used. */
options->config->is_cname = 0;
/* Set network parameters, such as the timeout period. */
options->ctl = aos_http_controller_create(options->pool, 0);
}
int main(int argc, char *argv[])
{
/* Call the aos_http_io_initialize method at the program entry to initialize global resources such as the network and memory. */
if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
exit(1);
}
/* The memory pool (pool) for memory management is equivalent to apr_pool_t. The implementation code is in the apr library. */
aos_pool_t *pool;
/* Create a new memory pool. The second parameter is NULL, which indicates that the new pool does not inherit from another memory pool. */
aos_pool_create(&pool, NULL);
/* Create and initialize options. This parameter includes global configuration information such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */
oss_request_options_t *oss_client_options;
/* Allocate memory from the memory pool to options. */
oss_client_options = oss_request_options_create(pool);
/* Initialize the client options oss_client_options. */
init_options(oss_client_options);
/* Initialize parameters. */
aos_string_t bucket;
aos_string_t object;
aos_table_t *params = NULL;
aos_http_request_t *req;
char *url_str;
apr_time_t now;
int64_t expire_time;
aos_str_set(&bucket, bucket_name);
aos_str_set(&object, object_name);
/* Resize the image to a fixed width and height of 100 px. */
params = aos_table_make(pool, 1);
apr_table_set(params, OSS_PROCESS, "image/resize,m_fixed,w_100,h_100");
req = aos_http_request_create(pool);
req->method = HTTP_GET;
req->query_params = params;
/* Specify the expiration time (expire_time) in seconds. */
now = apr_time_now();
expire_time = now / 1000000 + 10 * 60;
/* Generate a signed URL. */
url_str = oss_gen_signed_url(oss_client_options, &bucket, &object, expire_time, req);
printf("url: %s\n", url_str);
/* Release the memory pool. This is equivalent to releasing the memory allocated to resources during the request. */
aos_pool_destroy(pool);
/* Release the previously allocated global resources. */
aos_http_io_deinitialize();
return 0;
}
Referências
Para obter informações sobre os parâmetros compatíveis com o processamento de imagem, consulte Image processing.
Para acessar o código de exemplo completo de processamento de imagem, consulte o exemplo no GitHub.