Can't access data using " .DateTime " string

2024 11 10
1 个回答
回答已采纳
更新时间：2024 11 10
5 次查看（30 天）

0 个投票

hey, I'm taking image processsing ccourse from coursera by MATHWORKS. but there is a problem in accessing date and time of a picture in matlab using following given method in this course. please help in this query so that i can continue my course.

2 个评论
显示 无 隐藏 无

Stephen23
Stephen23 2024-11-10
What fields does METADATA contain? How did you create METADATA?
Laiba
Laiba 2024-11-10
metadata is created as shown below..... following are the fields that metadata contains.

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Star Strider
Star Strider 2024-11-10
Ran in:

0 个投票

Ran in:
Perhaps this —
imshow(imread('peppers.png'))
metadata = imfinfo('peppers.png')
metadata = struct with fields:
Filename: '/MATLAB/toolbox/matlab/matlab_images/png/peppers.png' FileModDate: '13-Jul-2023 20:26:13' FileSize: 287677 Format: 'png' FormatVersion: [] Width: 512 Height: 384 BitDepth: 24 ColorType: 'truecolor' FormatSignature: [137 80 78 71 13 10 26 10] Colormap: [] Histogram: [] InterlaceType: 'none' Transparency: 'none' SimpleTransparencyData: [] BackgroundColor: [] RenderingIntent: [] Chromaticities: [] Gamma: [] XResolution: [] YResolution: [] ResolutionUnit: [] XOffset: [] YOffset: [] OffsetUnit: [] SignificantBits: [] ImageModTime: '16 Jul 2002 16:46:41 +0000' Title: [] Author: [] Description: 'Zesty peppers' Copyright: 'Copyright The MathWorks, Inc.' CreationTime: [] Software: [] Disclaimer: [] Warning: [] Source: [] Comment: [] OtherText: [] AutoOrientedWidth: 512 AutoOrientedHeight: 384
DateTime = datetime(metadata.FileModDate)
DateTime = datetime
13-Jul-2023 20:26:13
.

6 个评论
显示 4更早的评论 隐藏 4更早的评论

Laiba
Laiba 2024-11-10
移动：Star Strider 2024-11-10
Thank you so much for answering, this solved above problem but there is one more problem now...
can you also tell how to solve this problem now?
Star Strider
Star Strider 2024-11-10
Ran in:
Ran in:
I cannot find anything with respect to the camera in the imfinfo properties.
imshow(imread('peppers.png'))
metadata = imfinfo('peppers.png')
metadata = struct with fields:
Filename: '/MATLAB/toolbox/matlab/matlab_images/png/peppers.png' FileModDate: '13-Jul-2023 20:26:13' FileSize: 287677 Format: 'png' FormatVersion: [] Width: 512 Height: 384 BitDepth: 24 ColorType: 'truecolor' FormatSignature: [137 80 78 71 13 10 26 10] Colormap: [] Histogram: [] InterlaceType: 'none' Transparency: 'none' SimpleTransparencyData: [] BackgroundColor: [] RenderingIntent: [] Chromaticities: [] Gamma: [] XResolution: [] YResolution: [] ResolutionUnit: [] XOffset: [] YOffset: [] OffsetUnit: [] SignificantBits: [] ImageModTime: '16 Jul 2002 16:46:41 +0000' Title: [] Author: [] Description: 'Zesty peppers' Copyright: 'Copyright The MathWorks, Inc.' CreationTime: [] Software: [] Disclaimer: [] Warning: [] Source: [] Comment: [] OtherText: [] AutoOrientedWidth: 512 AutoOrientedHeight: 384
DateTime = datetime(metadata.FileModDate)
DateTime = datetime
13-Jul-2023 20:26:13
Source = metadata.Source
Source = []
Here, the Source field is simply empty. See if that works with your image.
.
Laiba
Laiba 2024-11-10
thankyou you solved my problem
Star Strider
Star Strider 2024-11-10
My pleasure!
If my Answer helped you solve your problem, please Accept it!
.
Walter Roberson
Walter Roberson 2024-11-10
编辑：Walter Roberson 2024-11-10
According to the documentation for imfinfo()
  • DNG, JPEG, and TIFF only — If filename contains Exif tags, then info might include DigitalCamera or GPSInfo (global positioning system information) fields.
So this applies only to .dng, .jpg, .jpeg, .tif, and .tiff files, and only if the file includes EXIF tags, and even then only if the EXIF tags happen to include DigitalCamera or GPSInfo . If any of these three conditions are not satisfied, the DigitalCamera field will simply not be present. It will not "be present but empty" in such cases: it will literally not be present in such cases.
I was not able to find any case that potentially included a DateTime field.
Star Strider
Star Strider 2024-11-10
@Walter Roberson — Thank you for the clarification!

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Images 的更多信息

产品

版本

R2023a

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by