Image resizing and saving using imwrite
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hi...i need to resize the images to 512x512 and then save the image....m using imwrite to save but it saving it as blank images...my code is as below...plz help asap..
a=imread('1.jpg');
b=double(a)+1; %converting uint to double
c=imresize(b, [512 512]);
imwrite(c,'1f.jpg');
figure,imshow(a,[]);
figure,imshow(c,[]);
2 个评论
Jan
2014-4-14
@Horia: setting a flag is though to inform the admins about a question which conflicts with the terms of conditions. So please remove this flag and post a new question instead. Thanks.
Image Analyst
2014-4-14
I moved it.
采纳的回答
Jan
2012-4-27
0 个投票
If you work with images in DOUBLE format, limit the values to the interval [0, 1]. Therefore prefer IM2DOUBLE instead of double(a)+1.
4 个评论
kunal bhandari
2012-4-27
Horia
2014-4-13
At least when resizing .gif images, you should transform from 'double' to 'logical' before using resize.Otherwise,'imwrite' will save a black transparent image. I feel this aspect isn't covered under Matlab's 'Help'.
Jan
2014-4-13
@Horia: I do not agree. Converting to logical can work for black&white images only. For color images working in the DOUBLE format is sufficient, when you call imwrite with the correct inputs. If you have troubles, please post the corresponding code and the used type of the inputs.
Image Analyst
2014-4-14
Horia's "Flag" moved here:
I had to use: Convert grayscale to binary MyBinary = (MyGray > 0.5); when trying to resize a transparent .gif image. Otherwise (with double(imread(('image.gif'))), I had a correct image with imshow, but imwrite('...','TransparentColor',1) saved a totally black transparent image.
更多回答（1 个）
Image Analyst
2012-4-27
0 个投票
Don't convert to double. jpg images expect uint8 values.
3 个评论
kunal bhandari
2012-4-27
kunal bhandari
2012-4-27
Image Analyst
2012-4-27
If you want to save double images and will use them only in MATLAB, then I recommend saving them as a .mat file. If you want a visualization so that you can see them in other programs, like a jpg file, then use 255 * mat2gray() to scale to 0-255 before saving in a standard format like BMP, TIF, PNG, JPG, etc.
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