Mixing
Get the same NSData of PHAsset after save
Do you know is there any way to get the same NSData of Image ( JPG , PNG ) after save with PHPhotoLibrary or no?
OfC, iOS will modify some metadata and EXIF-- > ( Timestamp,... )data after save but, I'm asking about UIImage Data (include same EXIF data).
I didn't copy the exif in in my code here but it doesn't work
so Let's talk over the code:
Save Image and get hash
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
self.str1 = [tmpData MD5];
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetResourceCreationOptions *options = [[PHAssetResourceCreationOptions alloc] init];
options.originalFilename = @"XXX";
PHAssetCreationRequest * createReq = [PHAssetCreationRequest creationRequestForAsset];
[createReq addResourceWithType:PHAssetResourceTypePhoto data:tmpData options:options];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
NSLog(@"：%d",success);
}];
Load same Image :
[asset requestContentEditingInputWithOptions:0 completionHandler:^(PHContentEditingInput * _Nullable contentEditingInput, NSDictionary * _Nonnull info) {
PHImageRequestOptions * option = [[PHImageRequestOptions alloc] init];
option.synchronous = YES;
option.version = PHImageRequestOptionsVersionOriginal;
option.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
option.resizeMode = PHImageRequestOptionsResizeModeNone;
[[PHImageManager defaultManager] requestImageDataForAsset:asset options:option resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
UIImage * image = [UIImage imageWithData:imageData];
NSData * tmpDAt = UIImageJPEGRepresentation(image, 1.0);
NSString * md5 = [tmpDAt MD5];
if ([md5 isEqualToString:self.str1]) {
NSLog(@"My Expextation");
}
}];
The Intresting thing that I found is if I crop my image to 1*1 for test, I receive some error ( JPEGDecompressSurface : Picture decode failed: ) during save (It seems OS can't modify image) so I get the same hash before and after save :) !
ios objective-c phasset phphotolibrary
asked Nov 19 '18 at 11:58
Mo Farhand
784519
add a comment |
Do you know is there any way to get the same NSData of Image ( JPG , PNG ) after save with PHPhotoLibrary or no?
OfC, iOS will modify some metadata and EXIF-- > ( Timestamp,... )data after save but, I'm asking about UIImage Data (include same EXIF data).
I didn't copy the exif in in my code here but it doesn't work
so Let's talk over the code:
Save Image and get hash
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
self.str1 = [tmpData MD5];
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetResourceCreationOptions *options = [[PHAssetResourceCreationOptions alloc] init];
options.originalFilename = @"XXX";
PHAssetCreationRequest * createReq = [PHAssetCreationRequest creationRequestForAsset];
[createReq addResourceWithType:PHAssetResourceTypePhoto data:tmpData options:options];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
NSLog(@"：%d",success);
}];
Load same Image :
[asset requestContentEditingInputWithOptions:0 completionHandler:^(PHContentEditingInput * _Nullable contentEditingInput, NSDictionary * _Nonnull info) {
PHImageRequestOptions * option = [[PHImageRequestOptions alloc] init];
option.synchronous = YES;
option.version = PHImageRequestOptionsVersionOriginal;
option.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
option.resizeMode = PHImageRequestOptionsResizeModeNone;
[[PHImageManager defaultManager] requestImageDataForAsset:asset options:option resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
UIImage * image = [UIImage imageWithData:imageData];
NSData * tmpDAt = UIImageJPEGRepresentation(image, 1.0);
NSString * md5 = [tmpDAt MD5];
if ([md5 isEqualToString:self.str1]) {
NSLog(@"My Expextation");
}
}];
The Intresting thing that I found is if I crop my image to 1*1 for test, I receive some error ( JPEGDecompressSurface : Picture decode failed: ) during save (It seems OS can't modify image) so I get the same hash before and after save :) !
ios objective-c phasset phphotolibrary
asked Nov 19 '18 at 11:58
Mo Farhand
784519
add a comment |
Do you know is there any way to get the same NSData of Image ( JPG , PNG ) after save with PHPhotoLibrary or no?
OfC, iOS will modify some metadata and EXIF-- > ( Timestamp,... )data after save but, I'm asking about UIImage Data (include same EXIF data).
I didn't copy the exif in in my code here but it doesn't work
so Let's talk over the code:
Save Image and get hash
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
self.str1 = [tmpData MD5];
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetResourceCreationOptions *options = [[PHAssetResourceCreationOptions alloc] init];
options.originalFilename = @"XXX";
PHAssetCreationRequest * createReq = [PHAssetCreationRequest creationRequestForAsset];
[createReq addResourceWithType:PHAssetResourceTypePhoto data:tmpData options:options];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
NSLog(@"：%d",success);
}];
Load same Image :
[asset requestContentEditingInputWithOptions:0 completionHandler:^(PHContentEditingInput * _Nullable contentEditingInput, NSDictionary * _Nonnull info) {
PHImageRequestOptions * option = [[PHImageRequestOptions alloc] init];
option.synchronous = YES;
option.version = PHImageRequestOptionsVersionOriginal;
option.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
option.resizeMode = PHImageRequestOptionsResizeModeNone;
[[PHImageManager defaultManager] requestImageDataForAsset:asset options:option resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
UIImage * image = [UIImage imageWithData:imageData];
NSData * tmpDAt = UIImageJPEGRepresentation(image, 1.0);
NSString * md5 = [tmpDAt MD5];
if ([md5 isEqualToString:self.str1]) {
NSLog(@"My Expextation");
}
}];
The Intresting thing that I found is if I crop my image to 1*1 for test, I receive some error ( JPEGDecompressSurface : Picture decode failed: ) during save (It seems OS can't modify image) so I get the same hash before and after save :) !
ios objective-c phasset phphotolibrary
asked Nov 19 '18 at 11:58
Mo Farhand
784519
Do you know is there any way to get the same NSData of Image ( JPG , PNG ) after save with PHPhotoLibrary or no?
OfC, iOS will modify some metadata and EXIF-- > ( Timestamp,... )data after save but, I'm asking about UIImage Data (include same EXIF data).
I didn't copy the exif in in my code here but it doesn't work
so Let's talk over the code:
Save Image and get hash
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
self.str1 = [tmpData MD5];
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetResourceCreationOptions *options = [[PHAssetResourceCreationOptions alloc] init];
options.originalFilename = @"XXX";
PHAssetCreationRequest * createReq = [PHAssetCreationRequest creationRequestForAsset];
[createReq addResourceWithType:PHAssetResourceTypePhoto data:tmpData options:options];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
NSLog(@"：%d",success);
}];
Load same Image :
[asset requestContentEditingInputWithOptions:0 completionHandler:^(PHContentEditingInput * _Nullable contentEditingInput, NSDictionary * _Nonnull info) {
PHImageRequestOptions * option = [[PHImageRequestOptions alloc] init];
option.synchronous = YES;
option.version = PHImageRequestOptionsVersionOriginal;
option.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat;
option.resizeMode = PHImageRequestOptionsResizeModeNone;
[[PHImageManager defaultManager] requestImageDataForAsset:asset options:option resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
UIImage * image = [UIImage imageWithData:imageData];
NSData * tmpDAt = UIImageJPEGRepresentation(image, 1.0);
NSString * md5 = [tmpDAt MD5];
if ([md5 isEqualToString:self.str1]) {
NSLog(@"My Expextation");
}
}];
The Intresting thing that I found is if I crop my image to 1*1 for test, I receive some error ( JPEGDecompressSurface : Picture decode failed: ) during save (It seems OS can't modify image) so I get the same hash before and after save :) !
ios objective-c phasset phphotolibrary
ios objective-c phasset phphotolibrary
asked Nov 19 '18 at 11:58
Mo Farhand
784519
asked Nov 19 '18 at 11:58
Mo Farhand
784519
edited Nov 28 '18 at 21:13
asked Nov 19 '18 at 11:58
Mo Farhand
784519
asked Nov 19 '18 at 11:58
Mo Farhand
784519
asked Nov 19 '18 at 11:58
Mo Farhand
784519
784519
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
I presume the difference is due to your JPEGs having different timestamps (and possibly other differences) in their EXIF metadata.
Have you tried using UIImagePNGRepresentation instead of UIImageJPEGRepresentation? Hopefully PNG representations will match.
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
also, I tried withUIImagePNGRepresentationalso as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image
– Mo Farhand
Nov 21 '18 at 18:51
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
add a comment |
Jpeg compression is a Lossy form of compression. Every time you convert to Jpeg you will lose data. There is no way around it. Removing PHPhotoLibrary from the equation. If you run the following
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str1 = [tmpData MD5];
tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str2 = [tmpData MD5];
You will find that str1 and str2 are different.
If you want the same data you will have to either keep the original jpeg data that generated the image or use a loseless compression method like the one used within the PNG files.
answered Dec 11 '18 at 10:21
Spads
1,6011519
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
I presume the difference is due to your JPEGs having different timestamps (and possibly other differences) in their EXIF metadata.
Have you tried using UIImagePNGRepresentation instead of UIImageJPEGRepresentation? Hopefully PNG representations will match.
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
also, I tried withUIImagePNGRepresentationalso as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image
– Mo Farhand
Nov 21 '18 at 18:51
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
add a comment |
I presume the difference is due to your JPEGs having different timestamps (and possibly other differences) in their EXIF metadata.
Have you tried using UIImagePNGRepresentation instead of UIImageJPEGRepresentation? Hopefully PNG representations will match.
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
also, I tried withUIImagePNGRepresentationalso as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image
– Mo Farhand
Nov 21 '18 at 18:51
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
add a comment |
I presume the difference is due to your JPEGs having different timestamps (and possibly other differences) in their EXIF metadata.
Have you tried using UIImagePNGRepresentation instead of UIImageJPEGRepresentation? Hopefully PNG representations will match.
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
I presume the difference is due to your JPEGs having different timestamps (and possibly other differences) in their EXIF metadata.
Have you tried using UIImagePNGRepresentation instead of UIImageJPEGRepresentation? Hopefully PNG representations will match.
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
answered Nov 21 '18 at 15:39
Clafou
12.2k54580
12.2k54580
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
also, I tried withUIImagePNGRepresentationalso as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image
– Mo Farhand
Nov 21 '18 at 18:51
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
add a comment |
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
also, I tried withUIImagePNGRepresentationalso as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image
– Mo Farhand
Nov 21 '18 at 18:51
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
I was thinking about this too but what If I copy all of EXIF data for the new image ? (JPEG)
– Mo Farhand
Nov 21 '18 at 18:44
also, I tried with
UIImagePNGRepresentation also as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image– Mo Farhand
Nov 21 '18 at 18:51
also, I tried with
UIImagePNGRepresentation also as you know PNG doesn't keep the orientation so I check the md5 results in all orientation and doesn't match with the original one. I think it can be related to timestamp and ... but not sure as I'm copy all of EXIF information for the new image– Mo Farhand
Nov 21 '18 at 18:51
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
any idea? have you tried the same?
– Mo Farhand
Nov 23 '18 at 12:50
add a comment |
Jpeg compression is a Lossy form of compression. Every time you convert to Jpeg you will lose data. There is no way around it. Removing PHPhotoLibrary from the equation. If you run the following
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str1 = [tmpData MD5];
tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str2 = [tmpData MD5];
You will find that str1 and str2 are different.
If you want the same data you will have to either keep the original jpeg data that generated the image or use a loseless compression method like the one used within the PNG files.
answered Dec 11 '18 at 10:21
Spads
1,6011519
add a comment |
Jpeg compression is a Lossy form of compression. Every time you convert to Jpeg you will lose data. There is no way around it. Removing PHPhotoLibrary from the equation. If you run the following
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str1 = [tmpData MD5];
tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str2 = [tmpData MD5];
You will find that str1 and str2 are different.
If you want the same data you will have to either keep the original jpeg data that generated the image or use a loseless compression method like the one used within the PNG files.
answered Dec 11 '18 at 10:21
Spads
1,6011519
add a comment |
Jpeg compression is a Lossy form of compression. Every time you convert to Jpeg you will lose data. There is no way around it. Removing PHPhotoLibrary from the equation. If you run the following
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str1 = [tmpData MD5];
tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str2 = [tmpData MD5];
You will find that str1 and str2 are different.
If you want the same data you will have to either keep the original jpeg data that generated the image or use a loseless compression method like the one used within the PNG files.
answered Dec 11 '18 at 10:21
Spads
1,6011519
Jpeg compression is a Lossy form of compression. Every time you convert to Jpeg you will lose data. There is no way around it. Removing PHPhotoLibrary from the equation. If you run the following
UIImage * tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str1 = [tmpData MD5];
tmp = [[UIImage alloc] initWithData:tmpData];
tmpData =UIImageJPEGRepresentation(tmp, 1.0);
str2 = [tmpData MD5];
You will find that str1 and str2 are different.
If you want the same data you will have to either keep the original jpeg data that generated the image or use a loseless compression method like the one used within the PNG files.
answered Dec 11 '18 at 10:21
Spads
1,6011519
answered Dec 11 '18 at 10:21
Spads
1,6011519
answered Dec 11 '18 at 10:21
Spads
1,6011519
answered Dec 11 '18 at 10:21
Spads
1,6011519
1,6011519
add a comment |
add a comment |
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