Basic Image Processing

Last updated: 2021-06-09 14:27:13

Overview

This document provides an overview of APIs and SDK code samples related to basic image processing.

API	Operation
Scaling	Scales up/down an image
Cropping	Crops an image, including regular cropping, scaling and cropping, inscribed circle cropping, rounded corner cropping, and smart cropping
Rotation	Rotates an image, including common rotation and adaptive rotation
Format conversion	Converts the format of an image, optimizes GIF format, and performs progressive display
Quality conversion	Adjusts the quality of an image
Gaussian blurring	Blurs an image by a Gaussian function
Sharpening	Sharpens an image
Image watermarks	Adds a watermark to an image
Text watermarks	Adds a real-time text watermark to an image
Obtaining basic image information	Obtains the basic information (such as format, length, and height) about an image
Obtaining image EXIF data	Obtains the EXIF data of an image
Obtaining the image average hue	Obtains the average hue of an image
Removing metadata	Removes the image metadata, including the EXIF data
Quick thumbnail template	Provides an image processing template to generate thumbnails
Pipeline operator	Performs multiple operations on images in sequence

Scaling

Feature description

Tencent Cloud’s CI uses the imageMogr2 API to scale images.

Sample request

c
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);
options->config = cos_config_create(options->pool);
cos_str_set(&options->config->endpoint, TEST_COS_ENDPOINT);
cos_str_set(&options->config->access_key_id, TEST_ACCESS_KEY_ID);
cos_str_set(&options->config->access_key_secret, TEST_ACCESS_KEY_SECRET);
cos_str_set(&options->config->appid, TEST_APPID);
options->config->is_cname = is_cname;
options->ctl = cos_http_controller_create(options->pool, 0);
cos_str_set(&bucket, TEST_BUCKET_NAME);
params = cos_table_make(p, 1);
apr_table_addn(params, "imageMogr2/thumbnail/!50p", "");
cos_str_set(&file, "test.jpg");
cos_str_set(&object, "test.jpg");
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);

Cropping

Feature description

CI uses the imageMogr2 API to crop images, such as regular cropping, scaling and cropping, inscribed circle cropping, rounded corner cropping, and smart cropping.

Sample request

c
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);
options->config = cos_config_create(options->pool);
cos_str_set(&options->config->endpoint, TEST_COS_ENDPOINT);
cos_str_set(&options->config->access_key_id, TEST_ACCESS_KEY_ID);
cos_str_set(&options->config->access_key_secret, TEST_ACCESS_KEY_SECRET);
cos_str_set(&options->config->appid, TEST_APPID);
options->config->is_cname = is_cname;
options->ctl = cos_http_controller_create(options->pool, 0);
cos_str_set(&bucket, TEST_BUCKET_NAME);
params = cos_table_make(p, 1);
apr_table_addn(params, "imageMogr2/cut/600x600x100x10", "");
cos_str_set(&file, "test.jpg");
cos_str_set(&object, "test.jpg");
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);

Other basic image processing operations

Feature description

You can perform other basic processing operations on images by changing the value of the operation parameter. For example, you can rotate the image clockwise by 90 degrees as follows:

c
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);
options->config = cos_config_create(options->pool);
cos_str_set(&options->config->endpoint, TEST_COS_ENDPOINT);
cos_str_set(&options->config->access_key_id, TEST_ACCESS_KEY_ID);
cos_str_set(&options->config->access_key_secret, TEST_ACCESS_KEY_SECRET);
cos_str_set(&options->config->appid, TEST_APPID);
options->config->is_cname = is_cname;
options->ctl = cos_http_controller_create(options->pool, 0);
cos_str_set(&bucket, TEST_BUCKET_NAME);
params = cos_table_make(p, 1);
apr_table_addn(params, "imageMogr2/rotate/90", "");
cos_str_set(&file, "test.jpg");
cos_str_set(&object, "test.jpg");
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);

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