CN111583347A

CN111583347A - Image loading method and device, computer equipment and storage medium

Info

Publication number: CN111583347A
Application number: CN202010220644.7A
Authority: CN
Inventors: 雷郴湘
Original assignee: Ping An Property and Casualty Insurance Company of China Ltd
Current assignee: Ping An Property and Casualty Insurance Company of China Ltd
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2020-08-25

Abstract

The application relates to the field of image processing, and the loading efficiency of the image is improved by judging whether a target image exists in a local disk and loading the target image existing in the local disk according to a sub-thread and a main thread. In particular, to an image loading method, apparatus, computer device and storage medium, the image loading method comprising: acquiring an identification code of a target image, and determining whether a compressed image corresponding to the target image is stored in a local disk or not according to the identification code; if the local disk stores the compressed image corresponding to the target image, acquiring the compressed image from the local disk; the starter thread decodes the compressed image to obtain a bitmap corresponding to the target image; starting a main thread to render the bitmap, and loading the bitmap into a display screen; if the local disk does not store the compressed image corresponding to the target image, downloading the target image according to the uniform resource locator of the target image and loading the target image; and compressing the downloaded target image and storing the compressed target image into a local disk.

Description

Image loading method and device, computer equipment and storage medium

Technical Field

The present application relates to the field of image processing, and in particular, to an image loading method and apparatus, a computer device, and a storage medium.

Background

Most of the existing image loading methods are to asynchronously download images through a network, and then decode the images to generate a data stream to be rendered on a screen. The time consumption for downloading the image with a large volume is long, and the time consumption is also long in the process from decoding to rendering, so that a long blank time can appear when the image is loaded on a screen, and the user experience is influenced. In addition, asynchronous downloading over a network may be repeated for loading images of the same URL, resulting in wasted resources and a long time consuming downloading process.

Disclosure of Invention

The application provides an image loading method and device, computer equipment and a storage medium, which can improve the loading efficiency of images.

In a first aspect, the present application provides an image loading method, including:

acquiring an identification code of a target image, and determining whether a local disk stores a compressed image corresponding to the target image according to the identification code;

if the compressed image corresponding to the target image stored in the local disk is determined, acquiring the compressed image from the local disk;

the starter thread decodes the compressed image to obtain a bitmap corresponding to the target image;

starting a main thread to render the bitmap corresponding to the target image so as to load the bitmap corresponding to the target image into a display screen;

if the local disk is determined not to store the compressed image corresponding to the target image, downloading the target image according to the uniform resource locator of the target image and loading the target image;

and compressing and storing the downloaded target image into the local disk.

In a second aspect, the present application further provides an image loading apparatus, including:

the image searching module is used for acquiring an identification code of a target image and determining whether a local disk stores a compressed image corresponding to the target image according to the identification code;

the image acquisition module is used for acquiring a compressed image corresponding to the target image from the local disk if the local disk is determined to store the compressed image;

the image decoding module is used for starting a sub-thread to decode the compressed image to obtain a bitmap corresponding to the target image;

the image rendering module is used for starting a main thread to render the bitmap corresponding to the target image so as to load the bitmap corresponding to the target image into a display screen;

the image downloading module is used for downloading the target image and loading the target image according to the uniform resource locator of the target image if the local disk is determined not to store the compressed image corresponding to the target image;

and the image compression module is used for compressing the downloaded target image and storing the compressed target image into the local disk.

In a third aspect, the present application further provides a computer device comprising a memory and a processor;

the memory for storing a computer program;

the processor is configured to execute the computer program and implement the image loading method as described above when executing the computer program.

In a fourth aspect, the present application also provides a computer-readable storage medium storing a computer program which, when executed by a processor, causes the processor to implement the image loading method as described above.

The application discloses an image loading method, an image loading device, computer equipment and a storage medium, wherein whether a local disk stores a compressed image corresponding to a target image or not can be determined according to an identification code of the target image by obtaining the identification code; if the compressed image corresponding to the target image stored in the local disk is determined, the compressed image is obtained from the local disk, so that the image downloading times can be reduced; the compressed image is decoded through the sub-thread, and the decoded bitmap is rendered through the main thread, so that the bitmap corresponding to the target image is loaded into the display screen, the image loading time is shortened, and the image loading efficiency is effectively improved; when determining that the compressed image corresponding to the target image is not stored in the local disk, downloading the target image according to the uniform resource locator of the target image and loading the target image; and the downloaded target image is compressed and stored in a local disk, so that the image can be prevented from being repeatedly downloaded next time, resources are saved, and the image loading efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic flowchart of an image loading method provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of obtaining a compressed image from a local disk as provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of loading a compressed image onto a display screen provided by an embodiment of the present application;

FIG. 4 is a schematic block diagram of sub-steps of downloading the target image of FIG. 1;

FIG. 5 is a schematic diagram of downloading an image from a server as provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of a target image compressed and stored to a disk as provided by an embodiment of the present application;

FIG. 7 is a schematic diagram illustrating sub-steps of compressing and storing the target image of FIG. 1;

fig. 8 is a schematic block diagram of an image loading apparatus according to an embodiment of the present application;

FIG. 9 is a schematic block diagram of a sub-module of the image loading apparatus of FIG. 8;

FIG. 10 is a schematic block diagram of a sub-module of the image verification sub-module of FIG. 9;

fig. 11 is a schematic block diagram of a structure of a computer device according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The flow diagrams depicted in the figures are merely illustrative and do not necessarily include all of the elements and operations/steps, nor do they necessarily have to be performed in the order depicted. For example, some operations/steps may be decomposed, combined or partially combined, so that the actual execution sequence may be changed according to the actual situation.

It is to be understood that the terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of the present application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

The embodiment of the application provides an image loading method and device, computer equipment and a storage medium. The image loading method can be applied to the terminal, and can load the target image existing in the local disk according to the sub-thread and the main thread, so that the image loading efficiency is improved; if the target image does not exist in the local disk, the image is downloaded from the server and stored in the local disk, repeated downloading is avoided, resources are saved, and the image loading efficiency is improved.

Illustratively, the computer device may be a terminal. The server may be an independent server or a server cluster. The terminal can be an electronic device such as a smart phone, a tablet computer, a notebook computer, a desktop computer, a personal digital assistant and a wearable device.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

As shown in fig. 1, the image loading method includes steps S10 through S60.

Step S10, acquiring an identification code of the target image, and determining whether the compressed image corresponding to the target image is stored in the local disk according to the identification code.

It should be noted that the identification code may be used to determine a unique image; the identification code may also be used to identify images, search for images, verify images, encrypt images, and the like.

For example, whether an image corresponding to the identification code is stored may be searched in a local disk of the terminal according to the identification code of the image.

In the embodiment of the application, by obtaining a downloading operation of a user on an image, the image can be determined as a target image according to the downloading operation, a digital signature corresponding to the target image is obtained, and the digital signature corresponding to the target image is used as an identification code of the target image.

The downloading operation is an operation of downloading an image by a user. For example, a user selects an image and right-clicks an operation to save the image as another; or the user selects the image and downloads the image.

In some embodiments, if an image selected by a user is acquired and an operation of saving the image is right-clicked, determining that the operation is a downloading operation of the user on the image; and then determining the image as a target image according to the downloading operation.

It should be noted that the digital signature includes a 128-bit hash value, for example, the digital signature is a hash value of b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb391, where one hash value occupies two bytes. Since each image has a unique 128-bit hash value, the hash value is significantly different from image to image, and thus the images can be identified by the hash value.

In the embodiment of the application, the digital signature of the target image is used as the identification code of the target image. Thus, the identification code comprises a 128-bit hash value.

Illustratively, if the digital signature b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb391 of the target image is a 128-bit hash value, the identification code is b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb 391.

In other embodiments, the uniform resource locator URL of the target image may also be used as the identification code of the target image. Since each image has its unique corresponding uniform resource locator URL, the uniform resource locator URL can be used as the identification code of the target image.

Specifically, after the target image is determined and the identification code corresponding to the target image is acquired, whether the local disk stores the compressed image corresponding to the target image may be determined according to the identification code corresponding to the target image.

In some embodiments, whether the local disk stores a compressed image with an identification code consistent with that of the target image may be determined according to the identification code corresponding to the target image. And if the local disk stores a compressed image with the identification code consistent with that of the target image, acquiring the compressed image from the local disk. And if the local disk does not have a compressed image with the identification code consistent with that of the target image, downloading the target image from a server.

By obtaining the downloading operation of the user to the image, the target image can be determined according to the downloading operation and the identification code of the target image can be obtained, and then the compressed image corresponding to the target image can be searched in the local disk according to the identification code of the target image.

Step S20, if it is determined that the compressed image corresponding to the target image is stored in the local disk, acquiring the compressed image from the local disk.

It should be noted that the local disk stores a plurality of compressed images, and the compressed images are named by the identifier of the image. For example, when the image is compressed and stored in the local disk, the image identifier is used as the name value of the image, so that the unique compressed image can be determined by the name value of the compressed image.

As shown in FIG. 2, FIG. 2 is a schematic illustration of obtaining a compressed image from the local disk. Specifically, whether the local disk stores the compressed image corresponding to the target image is judged according to the identification code corresponding to the target image. And if the local disk is judged to store the compressed image corresponding to the target image, acquiring the compressed image from the local disk.

In some embodiments, the local disk is queried for the presence of a compressed image having an identification code that is consistent with the identification code of the target image. And if the local disk has a compressed image with the identification code consistent with the identification code of the target image, determining the compressed image as the compressed image corresponding to the target image and acquiring the compressed image.

The compressed image corresponding to the identification code of the target image in the local disk can be acquired by preferentially searching the compressed image corresponding to the identification code of the target image in the local disk, so that the loading speed of the image is improved, the downloading times from the server are reduced, and the network resources are saved.

And step S30, decoding the compressed image by the sub-thread to obtain a bitmap corresponding to the target image.

In the embodiment of the application, if the local disk stores the compressed image corresponding to the target image, the compressed image is obtained; and then calling a sub-thread to decode the compressed image to obtain a bitmap corresponding to the target image.

It should be noted that each application corresponds to a process, where a process may include one thread or multiple threads; for example, a process may include a main thread and multiple sub-threads. Each thread has a unique identifier, and the main thread and the sub-thread can be distinguished through the unique identifier.

In the embodiment of the application, a bitmap context corresponding to the compressed image is created through a sub-thread; and then adding bitmap information corresponding to the compressed image in the bitmap context through the sub-thread to obtain a bitmap corresponding to the compressed image.

It should be noted that the operation of decoding the compressed image is very memory consuming; if the operations of decoding and rendering the compressed images are completed in the main thread, when a plurality of compressed images in the main thread need to be decoded and rendered, a pause phenomenon occurs when the compressed images are loaded on a display screen. For example, a user may slide an image on a display screen, and a loading picture of a blank background may appear for a period of time. Therefore, the compressed image needs to be decoded by the sub-thread to obtain the bitmap corresponding to the compressed image, and then the bitmap corresponding to the compressed image is rendered by the main thread to load the bitmap corresponding to the compressed image into the display screen. As shown in fig. 3, fig. 3 is a schematic view of loading the compressed image to a display screen.

The compressed image is decoded first, and then the bitmap obtained by decoding is rendered, so that the decoding can be prevented from being performed when the compressed image is rendered, and an overlarge memory space is occupied; the image loading method and the device can also avoid the phenomenon of blocking when the image is loaded, reduce the loading time of the image and improve the experience degree of a user.

In some embodiments, the sub-thread decompresses the compressed image to obtain a bitmap corresponding to the compressed image.

Illustratively, the sub-thread reads a compressed image corresponding to the target image from the local disk into the RAM, and decodes the compressed image into an uncompressed bitmap form to obtain a bitmap corresponding to the compressed image. Wherein the RAM is a Random Access Memory (Random Access Memory).

It should be noted that a bitmap may also be referred to as a dot matrix image or a raster image, and is composed of a single point of a pixel. The color coding of the bitmap uses the optical intensity of the three primary colors red, green and blue to represent a color, so that the bitmap can be directly displayed on the display screen.

Specifically, before decoding the compressed image, the child thread needs to create a bitmap context corresponding to the compressed image. Illustratively, the child thread creates a bitmap context corresponding to rendering the compressed image according to a CGBitmapContextCreate function.

It should be noted that the bitmap context may be used to add rendering bitmap information to decode the compressed image to generate a bitmap. The rendering bitmap information may include the pixel format of the bitmap, such as the number of bits per component, the color space, and the alpha value, where the alpha value determines the transparency of the pixel.

Illustratively, the code for creating the bitmap context according to the CGBitmapContextCreate function is as follows:

CGContextRef CGBitmapContextCreate(

void*data,

size_t width,

size_t height,

size_t bitsPerComponent,

size_t bytesPerRow,

CGColorSpaceRef colorspace,

CGBitmapInfo bitmapInfo

)；

the parameter data is used for specifying a drawing memory address to be rendered; the parameter width is used for specifying the width of the bitmap, and the unit is a pixel; the parameter height is used for specifying the height of the bitmap, and the unit is a pixel; the parameter bitsPerComponent is used to specify the number of bits per element of a pixel in memory. For example, for a 32-bit pixel format and RGB color space, the number of bits is set to 8 bits. The parameter bytesPerRow is used to specify the number of bits each line of the bitmap occupies in memory, and one pixel occupies one bit. The parameter colorspace is used to specify the color space used by the bitmap context. The parameter bitmapInfo is a character string for specifying information as to whether the bitmap contains an alpha channel, a relative position of the alpha channel in the pixel, whether the pixel component is of a reshaped or floating point type, or the like.

Specifically, after the context of the bitmap is created, the child thread adds bitmap drawing information in the context of the bitmap to obtain a bitmap corresponding to the compressed image.

Illustratively, the terminal adds the information of the drawing bitmap in the context of the bitmap, and the implemented code is as follows:

const CGSize size＝size；

const size_t bitsPerComponent＝8；

const size_t bytesPerRow＝size.width*4；

CGBitmapContextCreate(calloc(sizeof(unsigned char),bytesPerRow*

size.height),size.width,size.height,

bitsPerComponent,bytesPerRow,

CGColorSpaceCreateDeviceRGB(),

kCGImageAlphaPremultipliedLast).

note that when the 32-bit pixel and color space of the bitmap are RGB, the number of bits per component is 8. kcgiagealphapreprultipliedlast represents the value of the alpha channel pre-multiplied by RGB.

By multiplying the value of the alpha channel with the RGB color space in advance, 3 multiplications can be avoided for each pixel during rendering. The multiplication result is calculated in advance and is directly displayed on a display screen when the bitmap is rendered, so that the rendering speed and the system performance can be improved.

And step S40, starting the main thread to render the bitmap corresponding to the target image so as to load the bitmap corresponding to the target image into a display screen.

Referring to fig. 3, fig. 3 is a schematic diagram of loading a compressed image onto a display screen. Specifically, after the sub-thread is started to decode the compressed image to obtain the bitmap corresponding to the target image, the main thread is also required to be started to render the bitmap corresponding to the target image, so as to load the bitmap corresponding to the target image into a display screen.

It should be noted that the rendering refers to a process of rendering the bitmap to the display screen. Illustratively, the rendering process may include: obtaining the coordinates of the bitmap, rasterizing the bitmap, calculating the fragment shader, rendering the bitmap from a frame buffer area to a screen and the like.

In the embodiment of the application, the main thread acquires coordinates of a bitmap corresponding to the compressed image, and then rasterizes the bitmap to acquire pixel points of the bitmap on a display screen; secondly, performing fragment shader calculation on the bitmap, and calculating the final displayed color value of each pixel point of the bitmap; and finally, rendering each pixel point of the bitmap to a frame buffer area, and rendering the pixel points to a display screen by the frame buffer area.

The target image is decoded by the starting sub-thread and the bitmap corresponding to the target image is rendered by the starting main thread, and the decoding and rendering processes are completed by different threads, so that the time for loading the image can be shortened, and the burden of a processor is lightened.

And step S50, if the local disk is determined not to store the compressed image corresponding to the target image, downloading the target image according to the uniform resource locator of the target image and loading the target image.

Specifically, whether the local disk stores a compressed image with an identification code consistent with that of the target image is judged according to the identification code corresponding to the target image. And if the local disk does not store the compressed image with the identification code consistent with the identification code of the target image, determining that the local disk does not store the compressed image corresponding to the target image.

In the embodiment of the application, after determining that the compressed image corresponding to the target image is not stored in the local disk, downloading the target image according to the uniform resource locator of the target image and loading the target image.

The Uniform Resource Locator (URL) is a compact representation of a location and an access method corresponding to a Resource that can be obtained from a server, and is an address of a standard Resource on the server. It should be noted that each file on the server has a unique URL that contains information indicating the location of the file and how the browser should handle it.

For example, the location of the file may be identified and determined by a uniform resource locator URL. As long as the file can be located, various operations, such as reading, updating, replacing, searching and the like, can be performed on the file.

Referring to fig. 4, the downloading of the target image and the loading of the target image according to the uniform resource locator of the target image in step S50 includes the following steps S51 to S55.

Step S51, acquiring the uniform resource locator corresponding to the target image, and determining the download address corresponding to the target image according to the uniform resource locator corresponding to the target image.

Illustratively, each image has its corresponding uniform resource locator URL, so the target image can be obtained.

Since the uniform resource locator URL corresponding to the target image includes the location information of the target image in the server, the specific location of the target image in the server can be determined according to the uniform resource locator URL.

It will be appreciated that the server stores a plurality of images, each stored at a different location; the specific location of the image may be determined by the uniform resource locator URL of the image.

In some embodiments, according to a uniform resource locator URL corresponding to the target image, the target image is found in the server and a specific position of the target image is determined, so that the target image can be downloaded from the specific position. Therefore, the uniform resource locator URL corresponding to the target image can be used as the download address corresponding to the target image. The target image can be downloaded from the server through the download address.

And step S52, downloading the image according to the download address to obtain a download image corresponding to the target image.

Since the step S51 determines the download address corresponding to the target image according to the URL corresponding to the target image, the image corresponding to the download address can be downloaded from the server according to the download address of the target image, so as to obtain the download image corresponding to the target image.

Referring to fig. 5, fig. 5 is a schematic diagram of downloading an image from a server. In some embodiments, according to the download address corresponding to the target image, the specific position of the target image in the server is linked and the image corresponding to the specific position is downloaded, so as to obtain a download image corresponding to the target image.

It can be understood that the downloaded image is not exactly the same as the target image, because during the downloading process, the downloaded image may be changed due to data loss and the like; thus, after the image is downloaded, the image needs to be verified.

Specifically, the downloaded image corresponding to the target image may be cached in a random access memory RAM. Since the reading speed of the RAM is high, the decoding and rendering speed of the downloaded image in the RAM is high, and therefore the loading efficiency of the downloaded image can be improved.

And step S53, performing digital signature verification on the downloaded image.

In this embodiment of the application, the identification code of the target image may be used as a first digital signature of the target image, and then a second digital signature corresponding to the downloaded image is obtained; and performing digital signature verification on the downloaded image according to the first digital signature and the second digital signature.

Since the digital signature of the target image is used as the identification code of the target image, the identification code of the target image can be used as the first digital signature of the target image. Wherein the first digital signature comprises a 128-bit hash value.

Illustratively, if the identification code of the target image is b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb391, the first digital signature of the target image is b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb 391.

Illustratively, the second digital signature corresponding to the downloaded image may be obtained according to a digital signature algorithm.

It should be noted that the digital signature algorithm is a message digest algorithm with a secret key, wherein the secret key includes a public key and a private key, and is used for verifying data integrity, authenticating data source and resisting denial, and conforms to the OSI reference model, private key signature and public key verification.

Illustratively, the digital signature algorithm may include the MD2 algorithm, the MD4 algorithm, the MD5 algorithm, the SHA-1 algorithm, the SHA-2 algorithm, and so forth. Wherein, the MD algorithms are all called Message-Digest Algorithm; the SHA algorithms are all referred to as Secure Hash Algorithm.

In the embodiment of the application, the second digital signature corresponding to the downloaded image is obtained according to the MD5 algorithm.

It should be noted that the MD5 algorithm is a message digest algorithm, which can generate an MD5 value from a string or a file according to a certain rule, wherein the MD5 value includes a 128-bit hash value. The hash value corresponding to each file is fixed, and when the content of the file changes, the hash values of the files are different, so that whether the file changes can be judged according to the hash values.

Specifically, the MD5 value of the downloaded image is calculated according to the MD5 algorithm, and a second digital signature corresponding to the downloaded image is obtained. And performing digital signature verification on the downloaded image according to the first digital signature and the second digital signature corresponding to the target image, and if the digital signature verification is successful, taking the downloaded image as the target image.

For example, if the 128-bit hash value corresponding to the second digital signature is consistent with the 128-bit hash value corresponding to the first digital signature, it is determined that the downloaded image passes the digital signature verification; and if the 128-bit hash value corresponding to the second digital signature is inconsistent with the 128-bit hash value corresponding to the first digital signature, determining that the downloaded image does not pass the digital signature verification.

By performing digital signature verification on the downloaded image, the downloaded image with errors can be prevented from being loaded into a display screen.

And step S54, if the downloaded image passes the digital signature verification, taking the downloaded image as a target image and loading the target image.

In some embodiments, if the second digital signature of the downloaded image is a 128-bit hash value b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb391, and the first digital signature is b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb 391. And judging that the downloaded image passes the digital signature verification and taking the downloaded image as the target image if the second digital signature of the downloaded image is consistent with the first digital signature of the target image and the downloaded image is completely identical to the target image.

Specifically, after the downloaded image verified by the digital signature is taken as the target image, the target image is decoded and rendered to be loaded into a display screen.

Illustratively, the starter thread decodes the target image to obtain a bitmap corresponding to the target image; and then starting a main thread to perform rendering operation on the bitmap corresponding to the target image so as to load the bitmap corresponding to the target image into a display screen.

And step S55, if the digital signature of the downloaded image is failed to verify, outputting a prompt of failure of downloading to remind the user to download the image again.

It should be noted that, if the downloaded image is changed, the MD5 value of the downloaded image is calculated by the MD5 algorithm, and the 128-bit hash value is also changed significantly, for example, the 128-bit hash value is 75a6ae14b40de30b7821b5ad90cb0d86791167c11d0834e30a99e205b23b 5446.

In some embodiments, if the 128-bit hash value corresponding to the second digital signature of the downloaded image is 75a6ae14b40de30b7821b5ad90cb0d86791167c11d0834e30a99e205b23b5446, and the first digital signature is b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb 391. And judging that the downloaded image does not pass the digital signature verification if the second digital signature of the downloaded image is not consistent with the first digital signature of the target image and the downloaded image is changed.

It can be understood that, if the second digital signature corresponding to the downloaded image is not identical to the first digital signature corresponding to the target image, it may be caused that an error occurs in the downloading process of the downloaded image, so that the content of the downloaded image is changed, and further, the MD5 value of the downloaded image is also changed.

In some embodiments, after determining that the digital signature of the downloaded image fails to verify, outputting a prompt of the download failure. For example by outputting a prompt for a download failure in a dialog box on the display screen to remind the user to re-download the image.

And step S60, compressing and storing the downloaded target image into the local disk.

In some embodiments, after the downloaded image verified by the digital signature is used as a target image and the target image is loaded to a display screen, the target image may be compressed and saved in the local disk.

Referring to fig. 6, fig. 6 is a schematic diagram of compressing and storing the target image in the local disk. Illustratively, the target image is compressed to obtain a compressed image corresponding to the target image, and then the compressed image is stored in the local disk, so that when the target image needs to be used next time, the compressed image corresponding to the target image can be searched from the local disk to obtain the target image.

By storing the compressed image into the local disk, the compressed image can be directly loaded from the local disk when the compressed image needs to be loaded next time, so that repeated downloading from a server is avoided, the time for loading the image is shortened, and resources are saved.

Referring to fig. 7, compressing and storing the downloaded target image to the local disk in step S60 includes the following steps S61 to S63.

And step S61, compressing the target image to obtain a compressed image corresponding to the target image.

Specifically, before compressing the target image, the format of the target image needs to be determined, and then a compression mode is selected according to the format of the target image.

Illustratively, the format of the image may include BMP format, GIF format, JPEG format, PNG format, TIFF format, and the like. Wherein the image in BMP format is a bitmap; the image in the GIF format is an animated image; the JPEG format is a common image format; the PNG format is an emerging network image format; the TIFF format is complex and stores a lot of information.

The JPEG format supports a lossy compression method, can remove redundant images and color data, and can obtain an extremely high compression rate and display a very rich and vivid image. The PNG format is the format which guarantees the least distortion at present, and the PNG format draws the advantages of the GIF format and the JPEG format; the PNG format has rich storage forms and has the color modes of GIF and JPEG. The PNG format supports lossless compression, and images in the PNG format can be compressed to the limit to facilitate network transmission, but all information about image quality can be retained.

In the embodiment of the present application, for convenience of description, the target image is preset to a JPEG format or a PNG format. By judging the format of the target image, the format corresponding to the target image can be determined.

Specifically, the format corresponding to the target image is determined according to the corresponding relationship between the format and the transparent form, and then the compression mode of the target image is determined. The correspondence between the format and the transparent form is shown in table 1.

Table 1 is a format comparison table

Format	Compression mode	Transparent form
			JPEG	Lossy compression	Do not support
PNG	Lossless compression	Support for

In the table, the formats include JPEG format and PNG format; the compression modes comprise lossy compression and lossless compression; the transparent form includes non-support transparency and support transparency. It should be noted that the transparent form means that the edge of the image can be smoothly blended with any background, thereby completely eliminating the jagged edge.

For example, if the target image supports a transparent form, it may be determined that the target image is in a PNG format, and a compression mode corresponding to the target image is lossless compression; and if the target image does not support the transparent form, judging that the target image is in a JPEG format, and the compression mode corresponding to the target image is lossy compression.

It should be noted that images with different formats can be compressed by different compression methods. Wherein, each compression mode can realize compression operation through a corresponding compression algorithm.

In some embodiments, if the target image is in JPEG format, the target image may be compressed using a lossy compression algorithm since the JPEG format supports lossy compression. For example, a lossy compression operation is performed on the target image using a JPEG compression function.

Illustratively, the JPEG compression function may be called: and carrying out lossy compression operation on the target image by UIImageJPEGRepressation to obtain a compressed image corresponding to the target image.

In other embodiments, if the target image is in PNG format, the target image may be compressed using a lossless compression algorithm since the PNG format supports lossy compression. For example, the target image is subjected to lossless compression using a PNG compression function.

Illustratively, the PNG compression function may be invoked: and carrying out lossless compression operation on the target image by UIImagePNGRepresentation to obtain a compressed image corresponding to the target image.

By determining the format of the target image, different compression algorithms can be selected in a targeted manner according to the format of the target image. The target image in JPEG format is compressed in loss mode, the compression rate can reach 90%, important low-frequency components can be reserved, and unimportant high-frequency components are lost. The target image in the PNG format is subjected to lossless compression, redundant or similar pixel points in the target image can be deleted, and any distortion of the target image cannot be caused.

By compressing the target image, the compressed image with smaller volume is obtained and stored in the local disk, and the occupied storage space is small. When the downloading operation of the user is obtained, if the compressed image is needed, the image can be directly read from the local disk without being repeatedly downloaded in the server, and the image loading efficiency is improved. Because the volume of the compressed image is small, the time consumption is less during the processes of decompressing and rendering the compressed image, and the loading speed is higher.

And step S62, acquiring the digital signature of the compressed image.

It should be noted that, since the pixels of the target image change after compression and the obtained digital signature corresponding to the compressed image changes, the digital signature of the compressed image needs to be recalculated.

Specifically, the MD5 value of the compressed image is calculated according to the MD5 algorithm, resulting in a third digital signature of the compressed image.

Illustratively, the terminal calculates an MD5 value of the compressed image according to an MD5 algorithm, and obtains a 128-bit hash value b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb391, i.e. a third digital signature of the compressed image.

And step S63, determining the name of the compressed image according to the digital signature of the compressed image, and storing the compressed image in the local disk.

In some embodiments, after determining the third digital signature of the compressed image, the third digital signature of the compressed image may be used as a name value of the compressed image and the compressed image may be stored in a folder of the local disk.

Exemplarily, if the third digital signature of the compressed image is b68k02aac9867448ab8146f2c dcf1bg78e5b8e2902423b73d6f51a7ed9fdb391, the third digital signature is used as the naming value of the compressed image; the compressed image, named b68k02aac9867448ab8146f2cdcf1bg78e5b8e2902423b73d6f51a7ed9fdb391, is then stored in the folder of the local disk.

In some embodiments, after the compressed image is stored in the local disk, if the downloading operation of the user on the image is obtained again, the image is used as the image to be downloaded, and the digital signature of the image to be downloaded is determined according to the downloading operation; and then inquiring whether a target image with a first digital signature consistent with the digital signature of the image to be downloaded exists in a Random Access Memory (RAM) according to the digital signature of the image to be downloaded.

When the image needs to be downloaded, whether the same image exists or not is preferentially inquired in the random access memory RAM, and the image loading speed can be effectively increased because the reading speed of the memory is higher than that of a local disk.

Illustratively, if a target image with a first digital signature consistent with the digital signature of the image to be downloaded exists in the random access memory RAM, the target image is loaded into a display screen. And if the target image with the first digital signature consistent with the digital signature of the image to be downloaded does not exist in the random access memory RAM, inquiring a compressed image with a third digital signature consistent with the digital signature of the image to be downloaded from a folder on the local disk, and loading the inquired compressed image into a display screen.

It should be noted that, if the to-be-downloaded image does not exist in the random access memory RAM, the reason may be that a thread for processing the target image is cancelled after the target image with the first digital signature consistent with the digital signature of the to-be-downloaded image is stored in the local disk. It is therefore necessary to read the image to be downloaded from the local disk.

In other embodiments, the URL of the compressed image may be used as a name value of the compressed image, and the compressed image may be stored in a folder of the local disk. If the downloading operation of the user on the compressed image is obtained again, an image with a name value consistent with the uniform resource locator corresponding to the compressed image can be searched in the local disk according to the uniform resource locator corresponding to the compressed image.

According to the image loading method provided by the embodiment, the target image can be determined by obtaining the downloading operation of the user on the image, and the identification code can be further determined according to the digital signature of the target image; the compressed image is decoded through the sub-thread, and the decoded bitmap is rendered through the main thread, so that the bitmap corresponding to the target image is loaded into the display screen, the image loading time is shortened, and the image loading efficiency is effectively improved; the image can be downloaded from the server by the uniform resource locator according to the target image; by carrying out digital signature verification on the downloaded image, the downloaded image with errors can be prevented from being loaded into a display screen; by compressing the downloaded target image, the compressed image with smaller volume can be stored in a local disk, and the occupied storage space is small. When the compressed image needs to be used again, repeated downloading is not needed, resources are saved, and the loading efficiency of the image is improved.

Referring to fig. 8, fig. 8 is a schematic block diagram of an image loading apparatus according to an embodiment of the present application, where the image loading apparatus is configured to execute the foregoing image loading method. Wherein, the image loading device can be configured in the terminal.

As shown in fig. 8, the image loading apparatus 200 includes: the image processing system comprises an image searching module 201, an image obtaining module 202, an image decoding module 203, an image rendering module 204, an image downloading module 205 and an image compression module 206.

The image searching module 201 is configured to obtain an identification code of a target image, and determine whether a compressed image corresponding to the target image is stored in a local disk according to the identification code.

In some embodiments, as shown in fig. 9, the image search module 201 includes: a download operation acquisition sub-module 2011 and a digital signature acquisition sub-module 2012.

The download operation obtaining sub-module 2011 is configured to obtain a download operation of the user on the image, and determine the target image according to the download operation.

The digital signature obtaining sub-module 2012 is configured to obtain a digital signature corresponding to the target image, and use the digital signature corresponding to the target image as the identification code of the target image.

An image obtaining module 202, configured to obtain the compressed image from the local disk if it is determined that the compressed image corresponding to the target image is stored in the local disk.

And the image decoding module 203 is configured to start a sub thread to decode the compressed image to obtain a bitmap corresponding to the target image.

In some embodiments, as shown in fig. 9, the image decoding module 203 includes: create sub-module 2031 and add sub-module 2032.

The creating sub-module 2031 is configured to create a bitmap context corresponding to the compressed image by a sub-thread.

The adding sub-module 2032 is configured to add bitmap information corresponding to the compressed image in the bitmap context through the child thread to obtain a bitmap corresponding to the compressed image.

And the image rendering module 204 is configured to start a main thread to render the bitmap corresponding to the target image, so as to load the bitmap corresponding to the target image into a display screen.

An image downloading module 205, configured to, if it is determined that the compressed image corresponding to the target image is not stored in the local disk, download the target image according to the uniform resource locator of the target image and load the target image.

In some embodiments, as shown in fig. 9, the image download module 205 includes: an address acquisition sub-module 2051, an image download sub-module 2052, an image verification sub-module 2053, an image loading sub-module 2054, and a download reminding sub-module 2055.

And an address obtaining submodule 2051, configured to obtain a uniform resource locator corresponding to the target image, and determine a download address corresponding to the target image according to the uniform resource locator corresponding to the target image.

And the image downloading submodule 2052 is configured to download an image according to the download address, so as to obtain a downloaded image corresponding to the target image.

And an image verification sub-module 2053, configured to perform digital signature verification on the downloaded image.

In some embodiments, as shown in fig. 10, the image validation sub-module 2053 includes: a first signature acquisition sub-module 2053-1, a second signature acquisition sub-module 2053-2, and a digital signature verification sub-module 2053-3.

The first signature obtaining sub-module 2053-1 is configured to use the identifier of the target image as a first digital signature of the target image.

And a second signature obtaining sub-module 2053-2, configured to obtain a second digital signature corresponding to the downloaded image.

And a digital signature verification sub-module 2053-3, configured to perform digital signature verification on the downloaded image according to the first digital signature and the second digital signature.

And the image loading submodule 2054 is configured to, if the downloaded image passes the digital signature verification, take the downloaded image as a target image and load the target image.

And a download reminding sub-module 2055, configured to output a download failure prompt to remind the user to download the image again if the digital signature of the downloaded image is a verification failure.

And the image compression module 206 is configured to compress and store the downloaded target image in the local disk.

In some embodiments, as shown in fig. 9, the image compression module 206 includes: a compression submodule 2061, a signature submodule 2062, and a storage submodule 2063.

The compression submodule 2061 is configured to compress the target image to obtain a compressed image corresponding to the target image.

A signature submodule 2062 for obtaining a digital signature of the compressed image.

The storage sub-module 2063 is configured to determine a name of the compressed image according to the digital signature of the compressed image, and store the compressed image in the local disk.

It should be noted that, as will be clear to those skilled in the art, for convenience and brevity of description, the specific working processes of the apparatus and the modules described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The apparatus described above may be implemented in the form of a computer program which is executable on a computer device as shown in fig. 11.

Referring to fig. 11, fig. 11 is a schematic block diagram of a computer device according to an embodiment of the present disclosure. The computer device may be a server.

Referring to fig. 11, the computer device includes a processor and a memory connected by a system bus, wherein the memory may include a nonvolatile storage medium and an internal memory.

The processor is used for providing calculation and control capability and supporting the operation of the whole computer equipment.

The internal memory provides an environment for running a computer program in the non-volatile storage medium, which, when executed by the processor, causes the processor to perform any of the image loading methods.

It should be understood that the Processor may be a Central Processing Unit (CPU), and the Processor may be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components, etc. Wherein a general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Wherein, in one embodiment, the processor is configured to execute a computer program stored in the memory to implement the steps of:

acquiring an identification code of a target image, and determining whether a local disk stores a compressed image corresponding to the target image according to the identification code; if the compressed image corresponding to the target image stored in the local disk is determined, acquiring the compressed image from the local disk; the starter thread decodes the compressed image to obtain a bitmap corresponding to the target image; starting a main thread to render the bitmap corresponding to the target image so as to load the bitmap corresponding to the target image into a display screen; if the local disk is determined not to store the compressed image corresponding to the target image, downloading the target image according to the uniform resource locator of the target image and loading the target image; and compressing and storing the downloaded target image into the local disk.

In one embodiment, the processor, when implementing acquiring the identification code of the target image, is configured to implement:

acquiring the downloading operation of a user on an image, and determining a target image according to the downloading operation; and acquiring a digital signature corresponding to the target image, and taking the digital signature corresponding to the target image as an identification code of the target image.

In one embodiment, when the processor implements a sub-thread to decode the compressed image to obtain a bitmap corresponding to the target image, the processor is configured to implement:

creating a bitmap context corresponding to the compressed image through a sub-thread; and adding bitmap information corresponding to the compressed image in the bitmap context through the sub-thread to obtain a bitmap corresponding to the compressed image.

In one embodiment, the processor, when enabling downloading of a target image according to its uniform resource locator and loading of the target image, is configured to enable:

acquiring a uniform resource locator corresponding to the target image, and determining a download address corresponding to the target image according to the uniform resource locator corresponding to the target image; downloading the image according to the downloading address to obtain a downloading image corresponding to the target image; performing digital signature verification on the downloaded image; and if the downloaded image passes the digital signature verification, taking the downloaded image as a target image and loading the target image.

In one embodiment, the processor, when performing digital signature verification on the downloaded image, is configured to perform:

taking the identification code of the target image as a first digital signature of the target image; acquiring a second digital signature corresponding to the downloaded image; and performing digital signature verification on the downloaded image according to the first digital signature and the second digital signature.

In one embodiment, the processor, after performing digital signature verification on the downloaded image, is further configured to perform:

and if the digital signature of the downloaded image is failed to verify, outputting a prompt of failure of downloading to remind the user to download the image again.

In one embodiment, when the processor is configured to compress and store the downloaded target image in the local disk, the processor is configured to:

compressing the target image to obtain a compressed image corresponding to the target image; acquiring a digital signature of the compressed image; and determining the name of the compressed image according to the digital signature of the compressed image, and storing the compressed image into the local disk.

The embodiment of the application further provides a computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, the computer program comprises program instructions, and the processor executes the program instructions to realize any image loading method provided by the embodiment of the application.

The computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiment, for example, a hard disk or a memory of the computer device. The computer readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital Card (SD Card), a Flash memory Card (Flash Card), and the like provided on the computer device.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An image loading method, comprising:

and compressing and storing the downloaded target image into the local disk.

2. The image loading method according to claim 1, wherein the obtaining of the identification code of the target image comprises:

acquiring the downloading operation of a user on an image, and determining a target image according to the downloading operation;

and acquiring a digital signature corresponding to the target image, and taking the digital signature corresponding to the target image as an identification code of the target image.

3. The image loading method according to claim 1, wherein the decoding of the compressed image by the initiator thread to obtain the bitmap corresponding to the target image comprises:

creating a bitmap context corresponding to the compressed image through a sub-thread;

and adding bitmap information corresponding to the compressed image in the bitmap context through the sub-thread to obtain a bitmap corresponding to the compressed image.

4. The image loading method according to claim 1, wherein the downloading the target image and loading the target image according to the uniform resource locator of the target image comprises:

acquiring a uniform resource locator corresponding to the target image, and determining a download address corresponding to the target image according to the uniform resource locator corresponding to the target image;

downloading the image according to the downloading address to obtain a downloading image corresponding to the target image;

performing digital signature verification on the downloaded image;

and if the downloaded image passes the digital signature verification, taking the downloaded image as a target image and loading the target image.

5. The image loading method according to claim 4, wherein the performing digital signature verification on the downloaded image comprises:

taking the identification code of the target image as a first digital signature of the target image;

acquiring a second digital signature corresponding to the downloaded image;

and performing digital signature verification on the downloaded image according to the first digital signature and the second digital signature.

6. The image loading method according to claim 4, wherein after the verifying the digital signature of the downloaded image, the method further comprises:

7. The image loading method according to any one of claims 1 to 6, wherein compressing and storing the downloaded target image in the local disk includes:

compressing the target image to obtain a compressed image corresponding to the target image;

acquiring a digital signature of the compressed image;

and determining the name of the compressed image according to the digital signature of the compressed image, and storing the compressed image into the local disk.

8. An image loading apparatus characterized by comprising:

9. A computer device, wherein the computer device comprises a memory and a processor;

the memory for storing a computer program;

the processor for executing the computer program and implementing the image loading method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, causes the processor to implement the image loading method according to any one of claims 1 to 7.