Questions tagged [jpeg]
The jpeg tag has no usage guidance.
27 questions
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1
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52
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pset4 recover doesn't recognize jpegs
I've been working on Recover for quite many hours now and I can't really understand what is wrong.
Here I share my commented code.
What I can tell you about its behavior is the following:
It does not ...
- 9
0
votes
1
answer
153
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CS50 PSet4 Recover fails Check50
I'm having trouble finding the issue with my code. It successfully recovers 50 JPEG files 000 - 049 which can all be opened and viewed and seem correct. But my code fails check50. Does anybody have ...
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1
answer
50
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CS50 Pset4 Logic Problem
I am 3 days into PSET 4 Recover.
In PSET 4 we are supposed to create a program which inputs a memory card and scans through that memory card for the signatures of lost JPEG files. Once the header of a ...
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1
answer
46
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pset4 - My recover programme compiles but doesn't generate JPEGs as expected
After 12hrs of banging my head against this, and having trawled Stack Exchange, I've decided that it's time to ask for help!
Really not sure where I'm going wrong, but suspect it's related to the ...
0
votes
1
answer
81
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Retrieving image from SQLite, "Invalid or Unsupported Image Format"
I am getting an Invalid or Unsupported Image Format when I open an image stored and retrieved in SQLite. When I input the convertToBinaryData file into the writeTofile function then the photo is ...
- 35
0
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1
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107
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Recover function in pset4
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
/* Open memory card
Repeat until end of card:
Read 512 bytes of data into buffer
If ...
0
votes
1
answer
148
views
pset4 recover - rick rolled - thinking about this the wrong way?
This is my humble, little code. The comments shows my though process:
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
if(argc != 2)
{
printf("...
0
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1
answer
79
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pset4 recover - doesn`t recover all files
Struggling with recover at this moment. My code creates just 8 pictures out of 50 - from 2nd to 9th. Other jpegs are also made but i am unable to see them due to "Invalid or Unsupported Image Format". ...
0
votes
1
answer
55
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recover.c producing random image 🙁
recover.c is always producing this image:
Here is my code:
#include <stdio.h>
#include <stdint.h>
typedef enum {false, true} bool; // Bool
int main(int argc, char *argv[])
{
if (...
- 201
0
votes
1
answer
112
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Problem Set 4 Recover Issues. I can't figure out why my code doesn't work
I'm busy with problem set 4, and I can't figure out why my code doesn't work. What seems odd is that the first line or two of a new jpeg will seem partially or fully correct, but thereafter the images ...
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1
answer
95
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Segmentation fault on recover pset4
My program compiles, but when I run it I get a segmentation fault and nothing else:
~/workspace/recover/ $ make recover
clang -fsanitize=integer -fsanitize=undefined -ggdb3 -O0 -std=c11 -Wall ...
- 15
0
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1
answer
73
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pset4 recover: too many JPEGs found
guys! I was solving recover, but my program finds way too many JPEGs. I believe that this is because of the following lines:
// starting bytes of jpeg are in [lower, upper]
uint8_t lower[4] = {0xff, ...
0
votes
2
answers
294
views
PSET4 RECOVER Can't Open JPEGS, I Have Tried Everything Please HELP!
so this is my second time posting about this pset, my code is below. No images will open, with the current code. However when I do get something to open it is just 1 file and it says invalid or ...
- 1
0
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1
answer
146
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No JPEG images printed in recover.c
Since my program compiles fine I am wondering why nothing seems to be outputted from it. I looked at a few threads, but the only close question I found was here
Pset4 recover.c compiles, but can'...
- 176
0
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2
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821
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Why data recovery isn’t an exact science?
I don't understand why it is said in Pset4 that "Odds are, if you find this pattern of four bytes on media known to store photos (e.g., my memory card), they demarcate the start of a JPEG. To be fair, ...
0
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1
answer
171
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PSET4 Recover Can't Open JPEGs in the IDE
I've recovered all 50 JPEGs and when I download them to my computer and change the name from (for example) 000.jpg%OA I can see the picture correctly. However, in the IDE,if I open the same JPEG I get ...
0
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1
answer
394
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Having some tough time with pset4 recover.c
I've hit a wall and would appreciate some of you more experienced people to help me through or point me in the right direction. Below is my code, and it generates 27 JPEGs all distorted (numberer 0 - ...
- 23
0
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1
answer
183
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Pset4 - Recover - Not able to find jpegs in card.raw
I'm stuck pretty early on the "Recover" problem. My code doesn't find any JPEGS in the file "card.raw'
Here's the relevant bit of my code:
#include <stdio.h>
#include <stdlib.h>
// ...
- 121
0
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1
answer
115
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jpegs do not exists on running recover.c
i have made a program to recover the jpegs i.e. resize.c . The code is :
http://pastebin.com/B0XkP9i9
the check 50 results:
check50 2016.recover recover.c
:) recover.c exists
:) recover.c compiles
:) ...
0
votes
1
answer
179
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recover images from raw file (pset4)
The code manages to identify the signature. However, it seems that it reads incorrect amount of bytes, because it's not identified again. Where did I do wrong?
#include <stdio.h>
#include <...
- 3
0
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1
answer
36
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pset4/recover: i see files but not all of it and nothing in it
when i run the cod i can see the files but when i open it i can't see any pictures and also not all of the 50 files showed only 21.
#include <stdio.h>
#include <stdint.h>
int main(void)
{...
- 15
0
votes
1
answer
159
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Pset4 recover.c compliles but can't open jpeg
During recover of pset4, I manage to make all the files are made but when opening, an error pops up.
/**
* recover.c
*
* Computer Science 50
* Problem Set 4
*
* Recovers JPEGs from a forensic ...
0
votes
1
answer
116
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Jpeg image files format not supported
I am not able to open the images properly, and here is my code
typedef uint8_t BYTE;
BYTE buffer[512];
char title[10];
int count =0;
FILE* fp = fopen("card.raw","r");
while(!feof(fp))
{
fseek(...
0
votes
1
answer
70
views
Why does my program return a blank jpeg?
I have started recover.c in pset4.
I have decided to approach the problem step by step, so first task is recovering the first jpeg. enter code here
FILE* file = fopen("card.raw", "r");
...
- 7
1
vote
2
answers
593
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PSET4 recover.c not quite working / 98% blank JPEGs
my first post and would appreciate some feedback. I'm taking CS50 online, and the course assumes a lot, especially from someone like me who's only taking up coding again after 15 years (think Basic &...
- 13
0
votes
1
answer
192
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Need help with "recover"
I can't figure out what's wrong with my code. File names are created successfully but all jpegs just show the corrupt thumbnail. I'm sure it has something to do with finding the start and end of the ...
- 101
1
vote
1
answer
584
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recover.c cannot detect jpeg signatures?
Trying to get my recover.c to work.
My program fread's 512 bytes into a buffer on every iteration of a loop.
The buffer is declared as so:
unsigned int* cfbfr = malloc(512);
Then, at the start of ...
- 13